Furylthiazole derivatives, processes for the preparation thereof and pharmaceutical composition comprising the same

Abstract: This invention relates to furylthiazole derivatives and pharmaceutically acceptable salts thereof which have antiulcer activity and H₂-receptor antagonism, to processes for the preparation thereof, to a pharmaceutical composition comprising the same and to a method for the treatment of ulcer in human being or animals.

Description: This invention relates to new furylthiazole derivatives and pharmaceutically acceptable salts thereof. More particularly, it relates to furylthiazole derivatives and pharmaceutically acceptable salts thereof which have antiulcer activity and H₂-receptor antagonism, to processes for the preparation thereof, to a pharmaceutical composition comprising the same and to a method for the treatment of ulcer in human being or animals. Accordingly, one object of this invention is to provide new furylthiazole derivatives and pharmaceutically acceptable salts thereof which possess antiulcer activity and H₂-receptor antagonism. Another object of this invention is to provide processes for the preparation of said furylthiazole derivatives and salt thereof. A further object of this invention is to provide a pharmaceutical composition comprising, as an active ingredient, said furylthiazole derivatives or pharmaceutically acceptable salts thereof. Still further object of this invention is to provide a therapeutical method for the treatment of ulcer in human being or animals. The furylthiazole derivatives of this invention are new and can be represented by the following general formula (I) : wherein R¹ and R² are each hydrogen, furoyl or C₁-C₆ alkyl which may have halogen; or R¹ and R² are linked together to form C₁-C₆ alkylene, R³ is hydrogen or C₁-C₆ alkyl, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted by nitro,furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n is 0 or 1, X is =CH- or =N-, R⁵ is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, R⁶ is hydrogen, C₁-C₆ alkyl, C₁-C₆ alkylthio, C₁-C₆ alkoxy, amino, mono or di(C₁-C₆)alkylamino, allylamino, propargylamino, hydroxy(C₁-C₆)alkylamino, C₁-C₆ alkoxy(C₁-C₆)alkylamino, or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino; A is C₁-C₆ alkylene or -CONH-; or A-R⁴ is imidazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, and Q is hydrogen, or C₁-C₆ alkyl. The object compound (I) or a salt thereof can be prepared by processes as illustrated in the following reaction schemes. wherein R¹, R², R³, R⁴, R⁵, R⁶, X, A and Q are each as defined above, R 1 / a is C₁-C₆ alkyl which may have halogen, R 4 / a is ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted with nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotionylamino, morpholinocarbonylamino, C₁-c₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, or C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, R 4 / b is furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, R 4 / c is furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, R 4 / d is C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, R 4 / e is hydroxy(C₁-C₆)alkylureido, R 6 / a is amino which may have mono or di(C₁-C₆)alkyl, allyl, propargyl, hydroxy(C₁-C₆)alkyl or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkyl, or C₁-C₆ alkoxy, R⁷ is C₁-C₆ alkyl or phenyl, R⁸ is amino-protective group consisting of C₁-C₆ alkanoyl and benzoyl, R⁹, R¹¹, R¹³, R¹⁵, R¹⁷ and R¹⁸ are each C₁-C₆ alkyl, R¹⁰ is C₁-C₆ alkanoyloxy, phenyl(C₁-C₆)alkoxy, C₁-C₆ alkoxy(C₁-C₆)alkoxy, tetrahydropyranyloxy or C₁-C₆ alkoxy, R¹² and R¹⁹ are each carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, R¹⁴ is hydrogen or C₁-C₆ alkyl, R¹⁶ is thiazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, triazolyl substituted with amino and C₁-C₆ alkyl, benzoisothiazolyl substituted with oxo, or benzothiadiazinyl substituted with oxo, X¹ is S or O, Y is C₁-C₆ alkylene, Z¹, Z², Z³, Z⁴ and Z⁵ are each halogen, and A¹ is C₁-C₆ alkylene or bond. Suitable "C₁-C₆ alkyl" and "(C₁-C₆)alkyl" moiety in the term "(C₁-C₆)alkyl which may have halogen" may be a straight or branched one such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl, in which the preferable one is C₁-C₄ alkyl and the more preferable one is methyl or ethyl. Suitable "halogen" may be chloro, bromo, fluoro or iodo. Suitable "(C₁-C₆) alkylene" and C₁-C₆ alkylene moiety formed by linkage of R¹ and R² may be straight or branched one such as methylene, ethylene, trimethylene, propylene, tetramethylene, pentamethylene or hexamethylene, in which the preferable one is C₁-C₄ alkylene and the most preferable one is ethylene. Suitable "C₁-C₆ alkoxy" may be methoxy , ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy or hexyloxy, in which the preferable one is C₁-C₄ alkoxy, the more preferable one is C₁-C₂ alkoxy and the most preferable one is methoxy. Suitable "(C₁-C₆)alkylcarbamoyl" may be the carbamoyl substituted with (C₁-C₆)alkyl (e.g. methyl, ethyl, propyl, isopropyl, butyl, pentyl or hexyl), and the preferable one is N-(C₁-C₆)alkylcarbamoyl (e.g. N-methylcarbamoyl, N-ethylcarbamoyl or N-isopropylcarbamoyl). Suitable "(C₁-C₆)alkoxycarbonyl" may be methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl or tert-butoxycarbonyl. Suitable "(C₁-C₆)alkanoyl" and "(C₁-C₆)alkanoyl" moiety in the term "(C₁-C₆)alkanoylamino" may be formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl or hexanoyl. Suitable "(C₁-C₆)alkoxycarbonyl" moiety in the term "(C₁-C₆)alkoxycarbonylamino" may be the ones as mentioned before for "C₁-C₆ alkoxycarbonyl". Suitable "(C₁-C₆)alkylsulfonyl" moiety in the term "(C₁-C₆)alkylsulfonylamino" may be mesyl, ethanesulfonyl or propanesulfonyl. Suitable "(C₁-C₆)alkoxy(C₁-C₆)alkanoyl" moiety in the term "(C₁-C₆)alkoxy(C₁-C₆)alkanoylamino" may be (C₁-C₆)alkanoyl as mentioned before substituted with (C₁-C₆)alkoxy (e.g. methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy or hexyloxy) and the preferable one may be methoxyacetyl or ethoxyacetyl. Suitable "(C₁-C₆)alkanoyloxy" may be formyloxy, acetyloxy, propionyloxy, butyryloxy, isobutyryloxy, valeryloxy, isovaleryloxy, pivaloyloxy or hexanoyloxy. Suitable "(C₁-C₆)alkylthio may be methylthio, ethylthio, propylthio, isopropylthio, butylthio, pentylthio or hexylthio. Suitable "(C₁-C₆)alkyl" moiety in the term "(C₁-C₆)alkylureido" and "(C₁-C₆)alkylthioureido" may be (C₁-C₆)alkyl as mentioned before and the preferable (C₁-C₆)alkylureido may be 3-(C₁-C₆)alkylureido (e.g. 3-methylureido, 3-ethylureido, 3-propylureido and 3-isopropylureido) and the preferable (C₁-C₆)alkylthioureido may be 3-(C₁-C₆)alkylthioureido (e.g. 3-methylthioureido), Suitable "furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoyl" moiety in the term "furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino" may be (C₁-C₆)alkylthio(C₁-C₆)alkanoyl as mentioned before substituted with furyl. Suitable "mono or di(C₁-C₆)alkylamino" may be methylamino, dimethylamino, ethylamino or butylamino. Suitable "hydroxy(C₁-C₆)alkylamino" may be hydroxymethylamino, hydroxyethylamino, or hydroxypropylamino. Suitable C₁-C₆ alkoxy(C₁-C₆)alkylamino" may be methoxymethylamino. Suitable "mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino" may be methylaminomethylamino, or dimethylaminoethylamino. Suitable "trihalo(C₁-C₆)alkyl" may be trifluoro(C₁-C₆)alkyl (e.g. trifluoromethyl or trifluoroethyl). Suitable pharmaceutically acceptable salts of the object compound (I) are conventional non-toxic salts and include an organic acid addition salt [e.g. formate, acetate, trifluoroacetate, maleate, tartrate, methanesulfonate, benzenesulfonate, toluenesulfonate], an inorganic acid addition salt [e.g. hydrochloride, hydrobromide, sulfate, phosphate], a salt with an acidic amino acid [e.g. aspartic acid salt, glutamic acid salt]. With respect to the salt of the compound (I-1) to (I-32) in the Processes 1 to 27, it is to be noted that these compounds are included within the scope of the compound (I), and accordingly the suitable examples of the salts of these compounds are to be referred to those as salts of these compounds are to be referred to those as exemplified for the object compound (I). Particularly, the preferred embodiments of R¹, R², R³, R⁴, R⁵, R⁶, A, X, n and Q are as follows. R¹ is hydrogen, furoyl; C₁-C₆ alkyl which may have halogen such as C₁-C₆ alkyl (e.g. methyl or ethyl), trihalo(C₁-C₆)alkyl (e.g. trifluoromethyl or trifluoroethyl); R² is hydrogen; or R¹ and R² are linked together to form C₁-C₆ alkylene (e.g. methylene or ethylene); R³ is hydrogen; C₁-C₆ alkyl (e.g. methyl); R⁴ is amino; carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl (e.g. methylcarbamoyl), sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl (e.g. methoxycarbonyl); ureido, thioureidosulfamoylamino, C₁-C₆ alkanoylamino (e.g. formylamino, acetylamino, propionylamino, butyrylamino, isobutyrylamino, or valerylamino), C₁-C₆ alkoxycarbonylamino (e.g. methoxycarbonylamino), C₁-C₆ alkylsulfonylamino (e.g. mesylamino), C₁-C₆ alkoxy(C₁-C₆)alkanoylamino (e.g. methoxyacetylamino), C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino (e.g. acetoxyacetylamino), C₁-C₆ alkylthio(C₁-C₆)alkanoylamino (e.g. methylthioacetylamino), benzoylamino optionally substituted by nitro (e.g. nitrobenzoylamino), furoylamino, thenoylamino, nicotionylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido such as 3-(C₁-C₆)alkylureido (e.g. 3-methylureido, 3-ethylureido, 3-propylureido, 3-isopropylureido), C₁-C₆ alkylthioureido such as 3-(C₁-C₆)alkylthioureido (e.g. 3-methylthioureido), C₁-C₆ alkanoylureido such as 3-(C₁-C₆)alkanoylureido (e.g. 3-acetylureido), allylureido, benzoylthioureido (e.g. 3-benzoylthioureido), furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino (e.g. furylmethylthioacetylamino), furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino (e.g. furylmethylsulfinylacetylamino), mono or di(C₁-C₆)alkylsulfamoylamino (e.g. methylsulfamoylamino, dimethylsulfsmoylamino), hydroxy(C₁-C₆)alkylureido such as 3-hydroxy(C₁-C₆)alkylureido (e.g. 3-hydroxyethylureido), C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido such as 3-C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido (e.g. 3-acetoxyethylureido); C₁-C₆ alkylisothioureido such as 2-C₁-C₆ alkylisothioureido (e.g. 2-methylisothioureido); thiazolylamino substituted with C₁-C₆ alkyl (e.g. 4-methylthiazolylamino), triazolylamino substituted with amino and/or C₁-C₆ alkyl (e.g. 3-aminotriazolylamino, 3-amino-1-methyltriazolylamino), benzoisothiazolylamino substituted with oxo (e.g. 1,1-dioxobenzoisothiazolylamino), benzothiadiazinylamino substituted with oxo and halogen (e.g. 1,1-dioxochlorobenzothiadiazinylamino); pyrimidinyl substituted with oxo and C₁-C₆ alkyl (e.g. 6-methyl-5-pentyl-4(1H)-pyrimidinon-2-yl); triazolyl substituted with amino (e.g. 3-aminotriazolyl); a group of the formula : wherein n is 0 or 1; X is =CH- or =N-; R⁵ is hydrogen; cyano; nitro; or carbamoyl, C₁-C₆ alkoxycarbonyl (e.g. methoxycarbonyl), sulfamoyl, C₁-C₆ alkylsulfonyl (e.g. mesyl, ethylsulfonyl), benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino (e.g. tosyl, methoxyphenylsulfonyl, bromophenylsulfonyl, or aminophenylsulfonyl), mono or di(C₁-C₆)alkylsulfamoyl (e.g. methylsulfamoyl or dimethylsulfamoyl); and R⁶ is hydrogen; C₁-C₆ alkyl (e.g. methyl); C₁-C₆ alkylthio (e.g. methylthio); C₁-C₆ alkoxy (e.g. methoxy); mono or di(C₁-C₆)alkylamino (e.g. methylamino, dimethylamino, butylamino), allylamino, propargylamino, hydroxy (C₁-C₆)alkylamino (e.g. hydroxyethylamino, hydroxypropylamino), C₁-C₆ alkoxy(C₁-C₆)alkylamino (e.g. methoxyethylamino) and mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino (e.g. dimethylaminoethylamino); A is C₁-C₆ alkylene (e.g. methylene or ethylene); -CONH-; or A-R⁴ is imidazolyl substituted with C₁-C₆ alkyl (e.g. 2-methylimidazolyl), triazolyl substituted with amino (e.g. 3-amino-1,2,4-triazolyl); and Q is hydrogen; or C₁-C₆ alkyl (e.g. methyl). The processes for preparing the object compounds (I) of the present invention are explained in detail in the following. Process 1 : The object compound (I) or a salt thereof can be prepared by reacting the compound (II) or a salt thereof with the compound (III). This reaction is usually conducted in a conventional solvent which does not adversely influence the reaction such as ethyl acetate, dichloromethane, chloroform, carbon tetrachloride, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, dioxane, water, alcohol [e.g. methanol, ethanol. ] acetic acid, formic acid, or a mixture thereof. The reaction temperature is not critical and the reaction is usually conducted under cooling to heating. Process 2 The object compound (I-2) or a salt thereof can be prepared by subjecting the compound (I-1) or a salt thereof to deacylation. Suitable method for this deacylation reaction may include conventional one such as hydrolysis, reduction. The hydrolysis is preferably carried out in the presence of a base or an acid. Suitable base may include, for example, an inorganic base such as alkali metal hydroxide (e.g. sodium hydroxide, potassium hydroxide. ), alkaline earth metal hydroxide (e.g. magnesium hydroxide, calcium hydroxide. ), alkali metal carbonate (e.g. sodium carbonate, potassium carbonate. ), alkaline earth metal carbonate (e.g. magnesium carbonate, calcium carbonate. ), alkali metal bicarbonate (e.g. sodium bicarbonate, potassium bicarbonate. ), alkali metal acetate (e.g. Sodium acetate, potassium acetate. ), alkaline earth metal phosphate (e.g. magnesium phosphate, calcium phosphate. ), alkali metal hydrogen phosphate (e.g. disodium hydrogen phosphate, dipotassium hydrogen phosphate. ), and an organic base such as tri(C₁-C₆)alkylamine (e.g. trimethylamine, triethylamine. ), picoline, N-methylpyrrolidine, N-methylmorpholine, 1,5-diazabicyclo[4,3,0]non-5-one, 1,4-diazabicyclo[2,2,2]octane, 1,5-diazabicyclo[5,4,0]undecene-5. The hydrolysis using a base is often carried out in water or a hydrophilic organic solvent or a mixed solvent thereof. Suitable acid may include an organic acid (e.g. formic acid, acetic acid, propionic acid) and an inorganic acid (e.g. hydrochloric acid, hydrobromic acid, sulfuric acid). The present hydrolysis is usually carried out in an organic solvent, water or a mixed solvent thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 3 The object compound (I-1) or a salt thereof can be prepared by reacting the compound (I-2) or a salt thereof with an acylating agent. The compound (I-2) may be used in the form of its conventional reactive derivative at the amino group. The acylating agent can be represented by the compound of the formula : R²⁰ - OH in which R²⁰ is carbamoyl, thiocarbamoyl, sulfamoyl, C₁-C₆ alkanoyl, C₁-C₆ alkoxycarbonyl, C₁-C₆ alkylsulfonyl, C₁-C₆ alkoxy(C₁-C₆)alkanoyl, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoyl, C₁-C₆ alkylthio(C₁-C₆)alkanoyl, benzoyl optionally substituted with nitro, furoyl, thenoyl, nicotinoyl, 1-oxonicotinoyl; morpholinocarbonyl, C₁-C₆ alkylcarbamoyl, C₁-C₆ alkylthiocarbamoyl, C₁-C₆ alkanoylcarbamoyl, allylcarbamoyl, benzoylthiocarbamoyl, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoyl, mono or di(C₁-C₆)alkylsulfamoyl, hydroxy(C₁-C₆)alkylcarbamoyl, or C₁-C₆ alkanoyloxy(C₁-C₆)alkylcarbamoyl, and its conventional reactive derivative at the hydroxy group. The suitable example may be an acid halide (e.g. acid chloride), an acid anhydride, an activated amide, an activated ester. In case the acyl group to be introduced is a carbamoyl type acyl, the acylating agent is usually used in the form of cyanate or isocyanate. The reaction is usually carried out in a conventional solvent such as water, alcohol [e.g. methanol, ethanol, ] acetone, dioxane, acetonitrile, chloroform, dichloromethane, ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, pyridine, acetic acid or any other organic solvent which does not adversely influence the reaction. These conventional solvents may also be used in a mixture with water. The reaction temperature is not critical, and the reaction is usually carried out under cooling to warming. The reaction may also be carried out in the presence of an inorganic or organic base such as an alkali metal bicarbonate, tri(C₁-C₆)alkylamine, pyridine, N-(C₁-C₆)alkylmorpholine, N,N-di(C₁-C₆)alkylbenzylamine. Process 4 The object compound (I-3) or a salt thereof can be prepared by reacting the compound (I-2) or a salt thereof with the compound (IV). This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 5 The object compound (I-4) or a salt thereof can be prepared by reacting the compound (I-3) or a salt thereof with the compound (V). This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. In case that the compound (V) is liquid, it can be also used as a solvent. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 6 The object compound (I-6) or a salt thereof can be prepared by subjecting the compound (I-5) or a salt thereof to hydrolysis reaction. This reaction is usually carried out in a conventional manner for transforming nitrile to amide. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as water, alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 7 The object compound (I-8) or a salt thereof can be prepared by subjecting the compound (I-7) or a salt thereof to elimination reaction of the amino-protective group. This reaction can be carried out in substantially the same manner as Process 2 , and therefore the reaction mode and reaction conditions [e.g. solvent, reaction temperature. ] of this reaction are to be referred to those as explained in Process 2 . Process 8 The object compound (I-9) or a salt thereof can be prepared by reacting the compound (I-8) or a salt thereof with the compound (VI). This reaction can be carried out in substantially the same manner as Process 1 , and therefore the reaction mode and reaction conditions [e.g. solvent, reaction temperature. ] of this reaction are to be referred to those as explained in Process 1 . Process 9 The object compound (I-10) or a salt thereof can be prepared by reacting the compound (I-2) or a salt thereof with the compound (VII). This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 10 The object compound (I-12) or a salt thereof can be prepared by reacting the compound (I-11) or a salt thereof with the compound (VIII). This reaction is usually carried out in the presence of dry hydrogen chloride gas. This reaction is usually carried out in a conventional solvent such as alcohol [e.g. methanol, ethanol. ], acetone, dioxane, acetonitrile, chloroform, methylene chloride, ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, pyridine or any other organic solvent which does not adversely influence the reaction. The reaction temperature is not critical, and the reaction is usually carried out under cooling to heating. The object compound (I-12) can be used as a starting compound of Process 15 mentioned hereinbelow with or without isolation. Process 11 The object compound (I-13) or a salt thereof can be prepared by reacting the compound (I-12) or a salt thereof with the compound (IX). This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 12-(i) The compound (XII) or a salt thereof can be prepared by reacting the compound (X) or a salt thereof with the compound (XI) or a salt thereof. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 12-(ii) The object compound (I-14) or a salt thereof can be prepared by reacting the compound (XII) or a salt thereof with the compound (XIII) or a salt thereof. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 13 The object compound (I-15) or a salt thereof can be prepared by subjecting the compound (I-11) or a salt thereof to reduction. The reduction may include, for example, reduction with an alkali metal borohydride (e.g. sodium borohydride. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out under cooling to heating. Process 14 The object compound (I-16) or a salt thereof can be prepared by reacting the compound (XIV) or a salt thereof with the compound (XV) or a salt thereof. This reaction can be carried out in substantially the same manner as Process 5 , and therefore the reaction mode and reaction conditions [e.g. solvent, reaction temperature. ] of this reaction are to be referred to those as explained in Process 5 . Process 15 The object compound (I-17) or a salt thereof can be prepared by subjecting the compound (I-12) or a salt thereof to hydrolysis. This reaction is usually carried out in a conventional solvent such as a mixture of water and alcohol [e.g. methanol. ] or any other solvent which does not adversely influence the reaction. The reaction temperature is not critical, and the reaction is usually carried out under cooling to heating. Process 16 The object compound (I-18) or a salt thereof can be prepared by subjecting the compound (I-17) or a salt thereof to amidation. This reaction is usually carried out in the presence of ammonia gas. This reaction is usually carried out in a conventional solvent such as alcohol [e.g. methanol, ethanol. ], acetone, dioxane, acetonitrile, chloroform, methylene chloride, ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, pyridine or any other organic solvent which does not adversely influence the reaction. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 17 The object compound (I-20) or a salt thereof can be prepared by reacting the compound (I-19) or a salt thereof with the compound (XVII). This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 18 The object compound (I-21) or a salt thereof can be prepared by reacting the compound (XVIII) or a salt thereof with hydrazine. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 19 The object compound (I-22) or a salt thereof can be prepared by reacting the compound (I-21) or a salt thereof with S-(C₁-C₆)alkylisothiourea or a salt thereof. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 20 The object compound (I-23) or a salt thereof can be prepared by subjecting the compound (I-22) or a salt thereof to ring closure. This reaction is usually carried out in the presence of ammonium hydroxide This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 21 The object compound (I-24) or a salt thereof can be prepared by reacting the compound (I-2) or a salt thereof with the compound (XIX) or a salt thereof. The reaction is usually carried out in a conventional solvent such as water, acetone, dioxane, acetonitrile, chloroform, dichloromethane, ethylene chloride, tetrahydrofuran, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, pyridine or any other organic solvent which does not adversely influence the reaction. These conventional solvents may also be used in a mixture with water. The reaction temperature is not critical, and the reaction is usually carried out under cooling to warming. The reaction may also be carried out in the presence of an inorganic or organic base such as an alkali metal bicarbonate, tri(C₁-C₆)alkylamine (e.g. triethylamine. ), pyridine, N-(C₁-C₆)alkylmorpholine, N,N-di(C₁-C₆)alkylbenzylamine. Process 22 The object compound (I-26) or a salt thereof can be prepared by oxidizing the compound (I-25) or a salt thereof. The oxidizing agent to be used in this reaction may include an inorganic peracid or a salt thereof (e.g. periodic acid, persulfuric acid, or sodium or potassium salt thereof. ), an organic peracid or a salt thereof (e.g. perbenzoic acid, m-chloroperbenzoic acid, performic acid, peracetic acid, chloroperacetic acid, trifluoroperacetic acid, or sodium or potassium salt thereof. ), ozone, hydrogen peroxide, urea-hydrogen peroxide, N-halosuccinimide (e.g. N-bromosuccinimide, N-chlorosuccinimide. ), hypochlorite compound (e.g. tert-butyl hypochlorite. ), permanganate (e.g. potassium permanganate. ), or any other conventional oxidizing agent which can oxidide a sulfide group to a sulfoxide group. The present reaction can also be carried out in the presence of a compound comprising Group Vb or VIb metal in the Periodic Table of elements, for example, tungstic acid, molybdic acid, vanadic acid, or an alkali or an alkaline earth metal salt thereof. The present oxidation reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as water, acetic acid, chloroform, methylene chloride, acetone, methanol, ethanol, tetrahydrofuran, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical and the reaction is preferably carried out under cooling to at ambient temperature. Process 23 The object compound (I-27) or a salt thereof can be prepared by reacting the compound (I-8) or a salt thereof with the compound (XX) or a salt thereof. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Process 24 The object compound (I-28) or a salt thereof can be prepared by reacting the compound (I-27) or a salt thereof with the compound (XXI) or a salt thereof. This reaction can be carried out in substantially the same manner as Process 5 , and therefore the reaction mode and reaction conditions [e.g. solvent, reaction temperature. ] of this reaction are to be referred to those as explained in Process 5 . Process 25 The object compound (I-30) or a salt thereof can be prepared by subjecting the compound (I-29) or a salt thereof to elimination reaction of the hydroxy-protective group. This reaction can be carried out in substantially the same manner as Process 2 , and therefore the reaction mode and reaction conditions [e.g. solvent, reaction temperature. ] of this reaction are to be referred to those as explained in Process 2 . Process 26 The object compound (I-31) or a salt thereof can be prepared by reacting the compound (I-2) or a salt thereof with the compound (XXII) or a salt thereof. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ] tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. The reaction may also be carried out in the presence of an inorganic or organic base such as tri(C₁-C₆)alkylamine (e.g. triethylamine. ). Process 27 The object compound (I-32) or a salt thereof can be prepared by subjecting the compound (I-13) or a salt thereof to hydrolysis. The hydrolysis is preferably carried out in the presence of a base or an acid. This reaction is usually carried out in a conventional solvent which does not adversely influence the reaction such as alcohol [e.g. methanol, ethanol, propanol. ], tetrahydrofuran, dioxane, dimethyl sulfoxide, N,N-dimethylformamide or a mixture thereof. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature or under warming or heating. Among the starting compounds, some of them are new and such compounds can be prepared by the methods of Preparation mentioned below and by any process known in the art for preparing structurally analogous compounds thereto. The compounds obtained by the above Processes 1 to 27 can be isolated and purified by a conventional method such as pulverization, recrystallization, column chromatography, reprecipitation. It is to be noted that each of the object compound (I) may include one or more stereoisomer such as optical isomer(s) and geometrical isomer(s) due to asymmetric carbon atom(s) and double bond(s) and all such isomers and mixture thereof are included within the scope of this invention. Furthermore, with regard to the compound (I), it is to be noted that the following formula(A) is well known to lie to tautomeric relation with the following formula (B), and accordingly, it is to be understood that both of the isomers are substantially the same. Accordingly, the both of the tautomeric forms are clearly included within the scope of the present invention. In the present specification, the object and starting compounds including the group of such tautomeric isomers are represented by using one of the expressions. The new furylthiazole derivatives (I) and pharmaceutically acceptable salts thereof possess antiulcer activity and H₂-receptor antagonism, and are useful for a therapeutic treatment of gastritis, ulcer (e.g. gastric ulcer, duodenal ulcer, anastomotic ulcer. ), Zollinger-Ellison syndrome, reflux esophagitis, upper gastrointestinal bleeding. For therapeutic purpose, the compound (I) and a pharmaceutically acceptable salt thereof of the present invention can be used in a form of pharmaceutical preparation containing one of said compounds, as an active ingredient, inadmixture with a pharmaceutically acceptable carrier such as an organic or inorganic solid or liquid excipient suitable for oral or parenteral administration. The pharmaceutical preparations may be capsules, tablets, dragees, granules, solution, suspension, emulsion. If desired, there may be included in these preparations, auxiliary substances, stabilizing agents, wetting or emulsifying agents, buffers and other commonly used additives. While the dosage of the compound (I) will vary depending upon the age and condition of the patient, an average single dose of about 0.1 mg, 1 mg, 10 mg, 50 mg, 100 mg, 250 mg, 500 mg and 1000 mg of the compound (I) may be effective for treating ulcer. In general, amounts between 0.1 mg/body and about 1,000 mg/body may be administered per day. In order to illustrate the usefulness of the object compound (I), the pharmacological test data of some representative compounds of the compound (I) are shown in the following. Test Compounds (a) 4-(5-Acetylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (b) 4-[5-(2-Cyano-3-methylguanidino)methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole (c) 2-(Diaminomethyleneamino-4-[5-(3-methylureido)methylfuran-2-yl]thiazole (d) 4-[5-(2-Amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole Test A (Gastric secretion in Heidenhain pouch dogs): Test Method Beagle dogs, weighing about 8-13 kg, were used for the study on gastric secretion. The animals were surgically provided with a vagally denervated Heidenhain pouch. One month or more later, the dogs were fasted overnight. Gastric secretion was stimulated by an intravenous infusion of tetragastrin (10 µg/kg/hr). Gastric samples were collected at 15 min intervals. After its volume was almost constant, test compound (3.2 mg/kg) suspended on 0.1% methyl cellulose solution was administered orally. Acid concentration was determined by titrating an aliquot to pH 7.0 with 0.1N sodium hydroxide solution using automatic titration (Hiranuma RAT-11 Type). Total acid output was calculated by multiplying total volume of gastric samples by acid concentration, and percentage change of total acid output was calculated by comparing with predosing value of test compound. Test Result Test Compound Inhibition (%) (a) 100 Test B (H₂-receptor antagonism in isolated guinea-pig atrium): Test Method The atrial strip isolated from guinea-pig was suspended under an initial tension 0.3 to 0.6 g in an organ bath containing Tyrode solution at 30°C, aerated 95%O₂-5%CO₂ gas. The beating rate and amplitude of contraction of the atrium were recorded by means of a transducer and a polygraph. Histamine (1 x 10⁻⁶ g/ml) was added to the bathing fluid and the increase in beating rate after dosing was measured. Addition of test compounds (1 x 10⁻⁶ g/ml) was made 30 minutes after washing out histamine. Inhibitory effect of test compound was calculated by comparing histamine-induced increases in beating rate before and 30 minutes after dosing with the test compounds. Test Results Test Compound H₂ Antagonism (%) (b) 90.7 (c) 89.1 Test C (Inhibition of stress ulcer): Test Method Five male Sprague-Dawley rats, aged 7 weeks and weighing about 200 g were used per group for the study on stress ulcer after the fast for 24 hours. Each animal was immobilized in a restrain cage and immersed to a level of the xiphoid in a water bath kept 22°C. Each of the test compounds (32 mg/kg) suspended in 0.1% methylcellulose solution was administered orally just before the immobilization. Seven hours later, the animals were sacrificed and their stomachs were removed. The stomach was then fixed with 2% formalin. The area of ulcers was measured for each animal, and percentage of inhibition was calculated by comparing the mean area of ulcers (mm²) in the test animals with that in the control animals. Test Result Test Compound Inhibition (%) (d) 86.6 Test D (Gastric secretion from lumen perfused stomach in anesthetized rats): Test Method Male Sprague-Dawley rats weighing about 250 g were used. Rats were deprived of food but allowed free access to water for 24 hours. The animals were anesthetized with 1.25 g/kg urethane intraperitoneally. The abdomen was opened and the gastric lumen was perfused with saline throughout the experiment. The perfusate was titrated by an autotitrator with 25 mM sodium hydroxide as a titrant. Gastric secretion was stimulated by intravenous infusion with histamine (3 mg/kg/hr). After reaching plateau, test compound (1 mg/kg) was given intravenously. Drug effect was expressed as maximal inhibition by acid output. Test Result Test Compound Inhibition (%) (d) 99 The following Preparations and Examples are given for the purpose of illustrating the present invention in more detail. Preparation 1 Aluminum chloride (34.1 g) was added to a mixture of 2-furylacetonitrile (11.4 g) and chloroacetyl chloride (12.7 ml) in dichloromethane (170 ml) under ice-cooling and the mixture was stirred for 10 minutes at the same temperature. After the ice bath was removed, the mixture was stirred for 75 minutes. The reaction mixture was added to a mixture of ice-water (300 ml) and dichloromethane (200 ml) and the separated dichloromethane layer was washed with water. To this solution was added a water and the mixture was adjusted to pH 8 with 20% aqueous potassium carbonate. The separated organic layer was washed with water and dried over magnesium sulfate. The solvent was removed by concentration to give [5-(chloroacetyl)furan-2-yl]acetonitrile (16.36 g). IR (film) : 3120, 2940, 2260, 2210, 1680, 1590, 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 4.33 (2H, s), 4.83 (2H, s), 6.64 (1H, d, J=4Hz), 7.55 (1H, d, J=4Hz) Preparation 2 A solution of methyl 3-(furan-2-yl)propanate (4.0 g) in 40% methylamine methanol solution (50 ml) was stirred for 5 hours at room temperature. The solvent was removed under reduced pressure to afford N-methyl-3-(furan-2-yl)proponamide (4.0 g). IR (Film) : 3300, 3100, 2940, 1660, 1610 cm⁻¹ NMR (CDCl₃, δ) : 2.48 (2H, t, J=7.5Hz), 2.76 (3H, d, J=5Hz), 2.98 (2H, t, J=7.5Hz), 5.72 (1H, br), 5.99 (1H, dd, J=3.8 and 0.5Hz), 6.26 (1H, dd, J=2.0 and 3.8Hz), 7.27 (1H, dd, J=2.0 and 0.5Hz) Preparation 3 A solution of methyl isocyanate (34.0 g) in methanol (30 ml) was added dropwise to a solution of furan-2-ylmethylamine (57.9 g) in methanol (300 ml) at 5 to 15°C. After being stirred at room temperature for three hours, the solvent was evaporated in vacuo. The residue was treated with diisopropyl ether (400 ml) to give N-(furan-2-ylmethyl)-N′-methylurea (81.9 g). mp : 80 to 81°C IR (Nujol) : 3350, 3320, 3150, 3125, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 2.60 (3H, d, J=5Hz), 4.23 (2H, d, J=5Hz), 5.85 (1H, q, J=5Hz), 61.8 (1H, d, J=3Hz), 6.35 (1H, dd, J=2Hz and 3Hz), 6.38 (1H, t, J=5Hz) and 7.55 (1H, d, J=2Hz) Preparation 4 The following compound was obtained according to a similar manner to that of Example 19. N-(Furan-2-ylmethyl)urea. mp : 88-92°C IR (Nujol) : 3450, 3300, 3190, 1660, 1610, 1545 cm⁻¹ NMR (DMSO-d₆, δ) : 4.16 (2H, d, J=6Hz), 5.55 (2H, s), 6.15-6.22 (1H, m), 6.32-6.42 (2H, m), 7.55 (1H, m) Preparation 5 A mixture of N-(furan-2-ylmethyl)urea (83.0 g), acetic anhydride (580 ml) and phosphoric acid (10 ml) was stirred for 15 minutes at 80°C, and then the mixture was evaporated in vacuo. To the residue was added a mixture of ethyl acetate, tetrahydrofuran and water and the mixture was adjusted to pH 7.5 with potassium carbonate. The separated organic layer was washed with brine and the mixture was dried over magnesium sulfate. The solvent was removed by concentration and triturated with a mixture of ethyl acetate and ether. The precipitate was collected by filtration to give 1-acetyl-3-(5-acetylfuran-2-ylmethyl)urea (32.17 g). IR (Nujol) : 3310, 3230, 3110, 1670 cm⁻¹ NMR (DMSO-d₆, δ) : 2.02 (3H, s), 2.37 (3H, s), 4.45 (2H, d, J=6Hz), 6.46 (1H, d, J=4Hz), 7.39 (1H, d, J=4Hz), 8.74 (1H, t, J=6Hz) The above filtrate was evaporated in vacuo. The residue was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (39:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo to give 1-(5-acetylfuran-2-ylmethyl)-1,3-diacetylurea (21.3 g). IR (Nujol) : 1780, 1670 cm⁻¹ NMR (DMSO-d₆, δ) : 2.28 (3H, s), 2.38 (3H, s), 2.40 (3H, s), 5.01 (2H, s), 6.60 (1H, d, J=4Hz), 7.41 (1H, d, J=4Hz), 11.34 (1H, s) Preparation 6 A solution of bromine (0.23 ml) in dichloromethane (5 ml) was dropwise added to a mixture of 1-acetyl-3-(5-acetylfuran-2-ylmethyl)urea (1.0 g) in dichloromethane (20 ml) at ambient temperature for 20 minutes and the mixture was stirred at the same temperature for 1.5 hours. The solvent was removed by concentration and residue was triturated with isopropyl ether to give 1-acetyl-3-[5-(bromoacetyl)furan-2-ylmethyl]urea (1.27 g). mp : 128-134°C (dec.) IR (Nujol) : 3290, 3110, 1670, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 2.02 (3H, s), 4.47 (2H, d, J=6Hz), 4.60 (2H, s), 6.53 (1H, d, J=4Hz), 7.62 (1H, d, J=4Hz), 8.77 (1H, t, J=6Hz), 10.46 (1H, s) Preparation 7 To a mixture of furan-2-ylacetonitrile (60.0 g) in dry isopropyl alcohol (600 ml) was bubbled with dry hydrogen chloride for 5 hours under ice-cooling and the mixture was stirred for 2 hours at the same temperature. The solvent and excess hydrogen chloride was removed by concentration in vacuo. To the solution of resulting residue in dry isopropyl alcohol (400 ml) was bubbled with an ammonia gas for 1.5 hours under ice-cooling and the mixture was stirred for 1.5 hours at the same temperature. Evaporation of the solvent gave a residue, which was purified by column chromatography on alumina eluting with a methanol. The eluted fractions containing the desired product were collected and evaporated in vacuo to give 2-(furan-2-yl)acetamidine hydrochloride (56.0 g). IR (film) : 3400-3000 (br), 1690, 1600, 1500 cm⁻¹ NMR (DMSO-d₆, δ) : 3.91 (2H, s), 6.42 (2H, s), 7.63 (1H, s), 9.08 (2H, br s), 9.38 (2H, br s) Preparation 8 The mixture of 2-(furan-2-yl)acetamidine hydrochloride (30.0 g), methyl 2-acetylheptanoate (34.8 g) and sodium methoxide (10.1 g) in methanol (300 ml) was stirred for 4.5 hours at ambient temperature, and then the solvent was removed by concentration. To the residue was added a mixture of ethyl acetate and water, and the mixture was adjusted to pH 9 with 6N-hydrochloric acid. The separated organic layer was washed with brine and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (19:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo to give 2-(furan-2-ylmethyl)-6-methyl-5-n-pentyl-4(1H)pyrimidinone (18.18 g). mp : 99-100°C IR (Nujol) : 1660, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 0.86 (3H, t, J=6Hz), 1.20-1.48 (6H, m), 2.17 (3H, s), 2.36 (2H, t, J=7Hz), 3.86 (2H, s), 6.26 (1H, d, J=3Hz), 6.39 (1H, m), 7.56 (1H, m), 12.37 (1H, s) Preparation 9 The following compounds were obtained according to a similar manner to that of Preparation 1 . (1) Methyl N-[5-(chloroacetyl)furan-2-ylmethyl]carbamate. mp : 86 to 91°C IR (Nujol) : 3330, 1600 (br), 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 3.59 (3H, s), 4.30 (2H, d, J=6Hz), 4.85 (2H, s), 6.56 (1H, d, J=3Hz), 7.59 (1H, d, J=3Hz) (2) N-Methyl-3-[5-(chloroacetyl)furan-2-yl]propanamide. mp : 110 to 115°C IR (Nujol) : 3300, 1640 cm⁻¹ NMR (CDCl₃, δ) : 2.79 (3H, d, J=4.7Hz), 4.47 (2H, s), 5.75 (1H, br), 6.26 (1H, d, J=3.6Hz), 7.23 (1H, d, J=3.6Hz) (3) N-[5-(Chloroacetyl)furan-2-ylmethyl]-N′-methylurea. mp : 125 to 126°C IR (Nujol) : 3370, 3330, 1680, 1635 cm⁻¹ NMR (DMSO-d₆, δ) : 2.55 (3H, d, J=4.5Hz), 4.27 (2H, d, J=6Hz), 4.84 (2H, s), 5.92 (1H, q, J=4.5Hz), 6.45 (1H, d, J=3Hz), 6.50 (1H, t, J=6Hz) and 7.55 (1H, d, J=3Hz) (4) 2-[5-(Chloroacetyl)furan-2-ylmethyl]-6-methyl-5-n-pentyl-4(1H)-pyrimidinone. mp : 136-139°C IR (Nujol) : 1685, 1645, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 0.80-0.94 (3H, m), 1.15-1.50 (6H, m), 2.16 (3H, s), 2.27-2.42 (2H, m), 4.01 (2H, s), 4.85 (2H, s), 6.59 (1H, d, J=4Hz), 7.59 (1H, d, J=4Hz), 12.49 (1H, s) (5) 2-Acetamidomethyl-5-chloroacetyl-3-methylfuran. mp : 94-100°C IR (Nujol) : 3340, 1690, 1650, 1550, 1520 cm⁻¹ NMR (DMSO-d₆, δ) : 1.82 (3H, s), 2.04 (3H, s), 4.27 (2H, d, J=6Hz), 4.80 (2H, s), 7.45 (1H, s), 8.43 (1H, t, J=6Hz) Preparation 10 The following compounds were obtained according to a similar manner to that of Example 1. (1) 2-Amino-4-[5-(3-methylureidomethyl)furan-2-yl]thiazole. mp : 196°C IR (Nujol) : 3400, 3300, 1610, 1575, 1515 cm⁻¹ NMR (DMSO-d₆, δ) : 2.56 (3H, d, J=5Hz), 4.20 (2H, d, J=6Hz), 5.83 (1H, q, J=5Hz), 6.22 (1H, d, J=3Hz), 6.34 (1H, t, J=6Hz), 6.43 (1H, d, J=3Hz), 6.63 (1H, s), 7.11 (4H, s) (2) 2-Amino-4-(5-cyanomethylfuran-2-yl)thiazole. mp : 215-216°C IR (Nujol) : 3390, 3310, 3150, 2270, 1640, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 4.21 (2H, s), 6.43 (1H, d, J=3Hz), 6.51 (1H, d, J=3Hz), 6.73 (1H, s), 7.15 (2H, s) Preparation 11 Benzoyl chloride (2.67 ml) was dropped to a refluxing solution of ammonium thiocyanate (1.92 g) in acetone (50 ml) and the mixture was refluxed for 15 minutes. 4-(5-Acetylaminomethylfuran-2-yl)-2-aminothiazole (5.20 g) was added portionwise to the refluxing mixture. After the mixture was refluxed for further two hours, the solvent was evaporated in vacuo and the residue was mixed with water and ethyl acetate. The resulting precipitate was collected by filtration and washed with ethyl acetate to afford 4-(5-acetylaminomethylfuran-2-yl)-2-(3-benzoylthioureido)thiazole (5.50 g). mp : 213 to 214°C IR (Nujol) : 3270, 1675, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 1.90 (3H, s), 4.37 (2H, d, J=6Hz), 6.40 (1H, d, J=3Hz), 6.80 (1H, d, J=3Hz), 7.42 (1H, s), 7.58-8.17 (5H, m), 8.40 (1H, d, J=6Hz), 12.00 (1H, s) and 14.08 (1H, s) Preparation 12 The following compounds were obtained according to a similar manner to that of Preparation 11. (1) 2-(3-Benzoylthioureido)-4-(5-cyanomethylfuran-2-yl)thiazole. mp : 207-210°C (dec.) IR (Nujol) : 3280, 2270, 1660, 1550, 1535 cm⁻¹ NMR (DMSO-d₆, δ) : 4.27 (2H, s), 6.52 (1H, d, J=3Hz), 6.81 (1H, d, J=3Hz), 7.40 (1H, s), 7.51-7.71 (3H, m), 8.00-8.04 (2H, m), 13.06 (1H, br s) (2) 2-(3-Benzoylthioureido)-4-[5-(3-methylureidomethyl)furan-2-yl)thiazole. mp : 213-214°C IR (Nujol) : 3340, 1675, 1630, 1590, 1545, 1520 cm⁻¹ NMR (DMSO-d₆, δ) : 2.58 (3H, d, J=5Hz), 4.26 (2H, d, J=6Hz), 5.89 (1H, q, J=5Hz), 6.31 (1H, d, J=3Hz), 6.44 (1H, t, J=6Hz), 6.74 (1H, d, J=3Hz), 7.37 (1H, s), 7.50-7.65 (2H, m), 7.65-7.78 (1H, m), 7.98-8.10 (2H, m) Preparation 13 A solution of sodium hydroxide (0.55 g) in water (5 ml) was added to a suspension of 4-(5-acetylaminomethylfuran-2-yl)-2-(3-benzoylthioureido)thiazole (5.40 g) in methanol (50 ml) and the mixture was stirred at 60°C for two hours. Following evaporation in vacuo, the residue was mixed with water (50 ml) and ethyl acetate (15 ml) and stirred for several minutes. The resulting precipitate was collected by filtration and washed with water and ethyl acetate to afford 4-(5-acetylaminomethylfuran-2-yl)-2-thioureidothiazole (2.95 g). mp : 231 to 232°C IR (Nujol) : 3310, 3270, 3190, 3140, 1635, 1620 cm⁻¹ NMR (DMSO-d₆, δ) : 1.86 (3H, s), 4.27 (2H, d, J=6Hz), 6.30 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 7.10 (1H, s), 8.28 (1H, t, J=6Hz), 8.33 (2H, br s) and 11.81 (1H, s) Preparation 14 The following compounds were obtained according to a similar manner to that of Preparation 13. (1) 4-(5-Cyanomethylfuran-2-yl)-2-thioureidothiazole. mp : 216-220°C IR (Nujol) : 3290, 3180, 3130, 2250, 1620, 1560, 1520 cm⁻¹ NMR (DMSO-d₆, δ) : 4.25 (2H, s), 6.50 (1H, d, J=3Hz), 6.72 (1H, d, J=3Hz), 7.23 (1H, s), 8.10 (1H, br s), 8.74 (1H, br s), 11.84 (1H, s) (2) 4-[5-(3-Methylureidomethyl)furan-2-yl]-2-thioureidothiazole. mp : 229°C IR (Nujol) : 3305, 1615, 1560 cm⁻¹ NMR (DMSO-d₆, δ) : 2.57 (3H, d, J=5Hz), 4.22 (2H, d, J=6Hz), 5.83 (1H, q, J=5Hz), 6.28 (1H, d, J=3Hz), 6.36 (1H, t, J=6Hz), 6.63 (1H, d, J=3Hz), 7.13 (1H, s) Preparation 15 A mixture of 4-(5-acetylaminomethylfuran-2-yl)-2-(3-benzoylthioureido)thiazole (39.5 g) in ethanol (400 ml) and conc. hydrochloric acid (87.1 ml) was heated under reflux for 15 hours and then the mixture was evaporated in vacuo. To the residue was added to a mixture of ethyl acetate and water and the mixture was adjusted to pH 9.5 with a potassium carbonate. The isolated precipitate was collected by filtration to give 4-(5-aminomethylfuran-2-yl)-2-thioureidothiazole (10.1 g). mp : 154-158°C IR (Nujol) : 3300, 3190, 3140, 1620, 1580, 1525 cm⁻¹ NMR (DMSO-d₆, δ) : 3.74 (2H, s), 6.31 (1H, d, J=3Hz), 6.61 (1H, d, J= 3Hz), 7.11 (1H, s) Preparation 16 A solution of potassium cyanate (9.6 g) in water (50 ml) was added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-thioureidothiazole (10.0 g) in N,N-dimethylformamide (80 ml) and 1N-hydrochloric acid (78.6 ml), and the mixture was stirred for 16 hours at ambient temperature. To the reaction mixture was added a water (100 ml) and isolated precipitate was collected by filtration to give 2-thioureido-4-(5-ureidomethylfuran-2-yl)thiazole (10.74 g). mp : 227-229°C IR (Nujol) : 3480, 3300, 1650, 1620, 1600, 1560, 1525 cm⁻¹ NMR (DMSO-d₆, δ) : 4.22 (2H, d, J=6Hz), 5.58 (2H, s), 6.29 (1H, d, J=3Hz), 6.41 (1H, t, J=6Hz), 6.66 (1H, d, J=3Hz), 7.13 (1H, s) Preparation 17 A mixture of 4-(5-cyanomethylfuran-2-yl)-2-thioureidothiazole (11.4 g) and methyl iodide (2.7 ml) in methanol (110 ml) and tetrahydrofuran (60 ml) was refluxed for 1.5 hours under stirring. Evaporation of the solvent gave a residue, which was triturated with ethyl acetate to give 2-[(amino)(methylthio)methyleneamino]-4-(5-cyanomethylfuran-2-yl)thiazole hydriodide (14.50 g). mp : 116-118°C IR (Nujol) : 3390, 3210, 2280, 1650, 1605, 1570 cm⁻¹ NMR (DMSO-d₆, δ) : 2.70 (3H, s), 4.30 (2H, s), 6.55 (1H, d, J=3Hz), 7.01 (1H, d, J=3Hz), 7.47 (1H, s) Preparation 18 The following compounds were obtained according to a similar manner to that of Preparation 17. (1) 2-[(Amino)(methylthio)methyleneamino]-4-[5-(3-methylureido)methylfuran-2-yl)thiazole hydriodide. mp : 164-167°C IR (Nujol) : 3320, 3100, 1620, 1590, 1570 cm⁻¹ NMR (DMSO-d₆, δ) : 2.58 (3H, s), 2.64 (3H, s), 4.25 (2H, s), 6.32 (1H, d, J=3Hz), 6.90 (1H, d, J=3Hz), 7.33 (1H, s), 9.79 (1H, br s) (2) 2-[(Amino)(methylthio)methyleneamino]-4-(5-ureidomethylfuran-2-yl)thiazole hydriodide. mp : 161-165°C IR (Nujol) : 3430, 3180-3310 (br), 1625, 1570, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 2.61 (3H, s), 4.23 (2H, s), 6.33 (1H, d, J=3Hz), 6.88 (1H, d, J=3Hz), 7.32 (1H, s), 9.50-10.00 (1H, br s) Preparation 19 A solution of (furan-2-yl)glyoxal (5.68 g), acetaldehyde (3.10 ml) and concentrated aqueous ammonia (30.9 ml) in ethanol (60 ml) was stirred for two hours at room temperature. The solvent was evaporated in vacuo and the residue was chromatographed on alumina by eluting with a mixture of chloroform and methanol (50:1, V/V) to give 4-(furan-2-yl)-2-methylimidazole (2.90 g). mp : 109 to 114°C IR (Nujol) : 3240, 1605 cm⁻¹ NMR (DMSO-d₆, δ) : 2.29 (3H, s), 6.44 (1H, dd, J=1Hz and 3Hz), 6.48 (1H, dd, J=2Hz and 3Hz), 7.18 (1H, s) and 7.56 (1H, dd, J=1Hz and 2Hz) Preparation 20 The following compound was obtained according to a similar manner to that of Preparation 1. 4-[5-Chloroacetylfuran-2-yl]-2-methylimidazole. mp : >300°C IR (Nujol) : 1670 cm⁻¹ NMR (DMSO-d₆, δ) : 2.32 (3H, s), 4.85 (2H, s), 6.75 (1H, d, J=3.5Hz), 7.58 (1H, s), 7.68 (1H, d, J=3.5Hz) and 14.65 (1H, br s) Example 1 A solution of 5-acetylaminomethyl-2-chloroacetylfuran (39.9 g) and diaminomethylenethiourea (21.9 g) in ethanol (400 ml) was refluxed for two hours with stirring. The solvent was evaporated in vacuo and the residue was dissolved in water (300 ml). The solution was basified with an aqueous potassium carbonate. The resulting precipitate was collected by filtration, washed with water and recrystallized from a mixture of methanol, tetrahydrofuran and diisopropyl ether to afford 4-(5-acetylaminomethylfuran-2-yl)-2-diaminomethyleneamino)thiazole (24.1 g). mp : 230 to 231°C IR (Nujol) : 3430, 3200, 3110, 3060, 1650 cm⁻¹ NMR (DMSO-d₆, δ) : 1.88 (3H, s), 4.26 (2H, d, J=6Hz), 6.25 (1H, d, J=3Hz), 6.56 (1H, d, J=3Hz), 6.73 (1H, s), 6.83 (4H, s), 8.24 (1H, t, J=6Hz) Anal. Calcd. for C₁₁H₁₃N₅O₂S : C 47.30, H 4.69, N 25.07 Found C 47.31, H 4.71, N 24.65 Example 2 A solution of 4-(5-acetylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (4.76 g) in 1N-hydrochloric acid (51.1 ml) was refluxed for 8 hours with stirring. The solution was made basic to pH 10 with an aqueous potassium carbonate. The resulting precipitate was collected by filtration and washed with water to afford 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (4.03 g). mp : 160 to 163°C IR (Nujol) : 3300 (broad), 1710, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.17 (2H, br s), 4.35 (2H, br s), 6.30 (1H, d, J=3Hz), 6.62 (1H, d, J=3Hz), 6.78 (1H, s), 7.00 (4H, br s) Example 3 Isobutyryl chloride (0.4 ml) was added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.8 g) and triethylamine (1.3 ml) in dichloromethane (16 ml) under ice-cooling and the mixture was stirred for 2 hours at the same temperature. The solvent was removed by concentration in vacuo and the residue was dissolved in a mixture of tetrahydrofuran, ethyl acetate and water. The mixture was adjusted to pH 10 with 4N sodium hydroxide under solution of aqueous layer in sodium chloride. The separated organic layer was washed with a brine and dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (9:1 to 4:1 V/V). The eluted fraction containing the desired product were collected and evaporated to give 2-(diaminomethyleneamino)-4-(5-isobutyrylaminomethylfuran-2-yl)thiazole (0.14 g). mp : 211-213°C IR (Nujol) : 3390, 3270, 3180, 1660, 1645, 1610, 1545 cm⁻¹ NMR (DMSO-d₆, δ) : 1.05 (6H, d, J=7Hz), 2.15-2.61 (1H, m), 4.26 (2H, d, J=5Hz), 6.22 (1H, d, J=3Hz), 6.56 (1H, d, J=3Hz), 6.72 (1H, s), 6.86 (4H, s), 8.15 (1H, t, J=5Hz) Example 4 Acetoxyacetyl chloride (0.5 g) was added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.8 g) and triethylamine (1.3 ml) in dichloromethane (16 ml) under ice-cooling and the mixture was stirred for 20 hours at ambient temperature. Evaporation of the solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated to give 4-(5-acetoxyacetylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole hydrochloride (0.41 g). mp : 250-253°C (dec.) IR (Nujol) : 3300, 1750, 1685, 1655, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 2.14 (3H, s), 4.36 (2H, d, J=5Hz), 4.53 (2H, s), 6.35 (1H, d, J=3Hz), 6.93 (1H, d, J=3Hz), 7.27 (1H, s), 8.24 (4H, s), 8.56 (1H, t, J=5Hz) Example 5 A mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.8 g) and isopropylisocyanate (0.46 ml) in tetrahydrofuran (16 ml) and methanol (6.6 ml) was stirred for 8 hours at ambient temperature. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (4:1, V/V). The eluted fraction containing the desired product were collected and evaporated to give 2-(diaminomethyleneamino)-4-[5-(3-isopropylureido)methylfuran-2-yl]thiazole (0.41 g) mp : 222-224°C (dec.) IR (Nujol) : 3440, 3320, 1665, 1615, 1585, 1570, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 1.06 (6H, d, J=7Hz), 3.40-3.89 (1H, m), 4.20 (2H, d, J=5Hz), 5.64 (1H, d, J=8Hz), 6.08 (1H, t, J=5Hz), 6.21 (1H, d, J=4Hz), 6.56 (1H, d, J=4Hz), 6.73 (1H, s), 6.86 (4H, s) Example 6 A solution of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (7.00 g) and dimethyl N-cyanodithioiminocarbonate (4.31 g) in N,N-dimethylformamide (70 ml) was stirred for 70°C for two hours. 40% Aqueous methylamine by weight (14 ml) was added to the warmed solution and the mixture was stirred for an additional one hour at the same temperature. After the solvent was evaporated in vacuo, the residue was chromatographed on alumina, eluting with a mixture of chloroform and methanol (9:1, V/V), followed by recrystallization from a mixture of methanol, tetrahydrofuran and diisopropyl ether to afford 2-(diaminomethyleneamino)-4-[5-(2-cyano-3-methylguanidino)methylfuran-2-yl]thiazole (4.05 g). mp : 231 to 232°C IR (Nujol) : 3440, 3310, 3200, 2160, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 2.70 (3H, d, J=5Hz), 4.32 (2H, d, J=6Hz), 6.23 (1H, d, J=3Hz), 6.53 (1H, d, J=3Hz), 6.70 (1H, s), 6.81 (4H, s), 6.98 (1H, q, J=5Hz), 7.35 (1H, t, J=6Hz) Example 7 A mixture of 2-(diaminomethyleneamino)-4-[5-(2-cyano-3-methylguanidino)methylfuran-2-yl]thiazole (2.28 g) and 4M-dioxanic hydrogen chloride (10 ml) in methanol (20 ml) was stirred at ambient temperature for 19 hours and further at 50°C for 5 hours. The resulting precipitate was collected by filtration, washed with methanol, and recrystallized from a mixture of methanol and water to afford 2-(diaminomethyleneamino)-4-[5-(2-carbamoyl-3-methylguanidino)methylfuran-2-yl]thiazole dihydrochloride (1.65 g). mp : 241 to 242°C IR (Nujol) : 3440-3100, 1715, 1685, 1665 cm⁻¹ NMR (DMSO-d₆, δ) : 2.93 (3H, d, J=5Hz), 4.73 (2H, d, J=6Hz), 6.60 (1H, d, J=3Hz), 6.97 (1H, d, J=3Hz), 7.33 (1H, s), 7.60 (2H, br s), 8.30 (4H, s), 9.08 (2H, br s), 10.43 (1H, br s), 12.63 (1H, br s) Anal. Calcd. for C₁₂H₁₆N₈O₂S·2HCl : C 35.21, H 4.43, N 27.38, Cl 17.22 Found C 35.06, H 4.29, N 27.25, Cl 17.43 Example 8 Benzoyl chloride (2.06 ml) was added dropwise to a refluxing suspension of ammonium isothiazonate (1.48 g) in acetone (40 ml). After the mixture was refluxed for 15 minutes, 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (4.00 g) was added by portions and the mixture was refluxed further for 3.5 hours. The solvent was evaporated in vacuo and the residue was mixed with ethyl acetate (20 ml) and water (50 ml) and stirred for one hour. The resulting precipitate was collected, washed with water and then ethyl acetate, followed by drying under reduced pressure to afford 2-(diaminomethyleneamino)-4-[5-{3-(benzoyl)thioureido}methylfuran-2-yl]thiazole (3.31 g). mp : 220 to 221°C (dec.) IR (Nujol) : 3430-3120, 1720 (shoulder), 1670 cm⁻¹ NMR (DMSO-d₆, δ) : 4.90 (2H, d, J=5Hz), 6.47 (1H, d, J=3Hz), 6.72 (1H, d, J=3Hz), 6.93 (1H, s), 7.23 (4H, s), 7.36-7.97 (5H, m), 11.19 (1H, t, J=5Hz), 11.43 (1H, br s) Example 9 A suspension of 2-(diaminomethyleneamino)-4-[5-{3-(benzoyl)thioureido}methylfuran-2-yl]thiazole (3.20 g) and sodium hydroxide (0.32 g) in methanol (30 ml) was stirred for 60°C for one hour. The reaction mixture was cooled in an ice bath and the resulting precipitate was collected by filtration and washed with methanol to afford 2-(diaminomethyleneamino)-4-(5-thioureidomethylfuran-2-yl)thiazole (1.73 g). mp : 177 to 179°C IR (Nujol) : 3370, 3180, 1650, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.56 (2H, d, J=5Hz), 6.30 (1H, d, J=3Hz), 6.59 (1H, d, J=3Hz), 6.76 (1H, s), 6.84 (4H, s), 7.12 (2H, s), 7.93 (1H, t, J=5Hz) Example 10 A suspension of 2-(diaminomethyleneamino)-4-(5-thioureidomethylfuran-2-yl)thiazole (0.70 g) and chloroacetone (0.22 g) in ethanol (15 ml) was refluxed for 4 hours with stirring. The solvent was evaporated in vacuo and the residue was recrystallized from a mixture of methanol and diisopropyl ether to afford 2-(diaminomethyleneamino)-4-[5-(4-methylthiazol-2-yl)aminomethylfuran-2-yl]thiazole (0.66 g). mp : 193 to 194°C IR (Nujol) : 3300, 3180, 3120, 1685 cm⁻¹ NMR (DMSO-d₆, δ) : 2.20 (3H, s), 4.52 (2H, s), 6.25 (1H, s), 6.47 (1H, d, J=3Hz), 7.00 (1H, d, J=3Hz), 7.30 (1H, s), 8.33 (4H, s) Anal. Calcd. for C₁₃H₁₄N₆OS₂·HCl : C 42.10, H 4.08, N 22.66 Found C 41.82, H 4.23, N 22.53 Example 11 A mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.80 g) and ethyl tosylformimidate (0.77g) in methanol (10 ml) was stirred for 5 hours at ambient temperature. The reaction mixture was diluted with diisopropyl ether (10 ml) and the resulting precipitate was collected by filtration. The product was purified by column chromatography on silica gel eluting with chloroform-methanol (9:1, V/V), followed by recrystallization from a mixture of methanol, tetrahydrofuran and diisopropyl ether to afford 2-(diaminomethyleneamino)-4-(5-tosyliminomethylaminomethylfuran-2-yl)thiazole (0.46 g). mp : 141 to 142°C IR (Nujol) : 3370, 1620 (shoulder), 1605, 1330, 1145 cm⁻¹ NMR (DMSO-d₆, δ) : 2.39 (3H, s), 4.46 (2H, d, J=5Hz), 6.33 (1H, d, J=3Hz), 6.56 (1H, s), 6.58 (1H, d, J=3Hz), 6.86 (4H, s), 7.28 (2H, d, J=8Hz), 7.65 (2H, d, J=8Hz), 8.14 (1H, d, J=5Hz), 9.10-9.27 (1H, m) Anal. Calcd. for C₁₇H₁₈N₆O₃S₂·H₂O : C 46.78, H 4.82, N 19.25, H₂O 4.13 Found C 46.86, H 4.59, N 18.78, H₂O 3.39 Example 12 The following compound was obtained according to a similar manner to that of Example 4 . 2-(Diaminomethyleneamino)-4-(5-morpholinocarbonylaminomethylfuran-2-yl)thiazole hydrochloride. mp : 214-215°C IR (Nujol) : 3370, 3320, 3200, 1680, 1615, 1600 cm⁻¹ NMR (DMSO-d₆, δ) : 3.19-3.47 (4H, m), 3.47-3.76 (4H, m), 4.31 (2H, d, J=5Hz), 6.33 (1H, d, J=3Hz), 6.94 (1H, d, J=3Hz), 7.12 (1H, t, J=5Hz), 7.27 (1H, s), 8.21 (4H, s) Example 13 The following compound was obtained according to a similar manner to that of Example 6 . 2-(Diaminomethyleneamino)-4-[5-{N-(1-methylamino-2-nitrovinyl)aminomethyl}furan-2-yl]thiazole. mp : 238-239°C IR (Nujol) : 3350, 1610, 1550, 1380 cm⁻¹ NMR (DMSO-d₆, δ) : 2.85 (3H, d, J=4Hz), 4.45 (2H, d, J=5Hz), 6.38 (1H, d, J=3Hz), 6.55 (1H, s), 6.61 (1H, d, J=3Hz), 6.76 (1H, s), 6.84 (4H, s) Anal. Calcd. C 42.72, H 4.48, N 29.06 Found C 42.77, H 4.53, N 28.96 Example 14 The following compound was obtained according to a similar manner to that of Example 5 . 2-(Diaminomethyleneamino)-4-[5-(3-methylureido)methylfuran-2-yl]thiazole. mp : 218-219°C (dec.) IR (Nujol) : 3400, 3330, 1630, 1590, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 2.54 (3H, d, J=5Hz), 4.17 (2H, d, J=5Hz), 5.56-5.85 (1H, m), 6.06-6.34 (1H, m), 6.17 (1H, d, J=3Hz), 6.51 (1H, d, J=3Hz), 6.68 (1H, s), 6.79 (4H, s) Example 15 The following compounds were obtained according to a similar manner to that of Example 3 . 2-(Diaminomethyleneamino)-4-(5-propionylaminomethylfuran-2-yl)thiazole. mp : 192-194°C (dec.) IR (Nujol) : 3380, 3290, 3110, 1660, 1615, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 1.06 (3H, t, J=7Hz), 2.16 (2H, q, J=7Hz), 4.28 (2H, d, J=5Hz), 6.25 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.74 (1H, s), 6.86 (4H, s), 7.18 (1H, t, J=5Hz) 2-(Diaminomethyleneamino)-4-[5-(2-methoxyacetylaminomethyl)furan-2-yl]thiazole. mp : 201-202°C (dec.) IR (Nujol) : 3430, 3370, 3110, 1670, 1640, 1600, 1555 cm⁻¹ NMR (DMSO-d₆, δ) : 3.33 (3H, s), 3.86 (2H, s), 4.33 (2H, d, J=5Hz), 6.24 (1H, d, J=3Hz), 6.56 (1H, d, J=3Hz), 6.73 (1H, s), 6.86 (4H, s), 8.20 (1H, t, J=5Hz) 2-(Diaminomethyleneamino)-4-(5-nicotinoylaminomethylfuran-2-yl]thiazole. mp : 224-225°C IR (Nujol) : 3480, 3400, 3350, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 4.51 (2H, d, J=5Hz), 6.33 (1H, d, J=3Hz), 6.57 (1H, d, J=3Hz), 6.73 (1H, s), 6.82 (4H, s), 7.46 (1H, dd, J=4 and 8Hz), 8.17 (1H, dt, J=2 and 8Hz), 8.65 (1H, dd, J=2 and 4Hz), 8.98 (1H, d, J=2Hz), 9.13 (1H, t, J-5Hz) Anal. Calcd. C 49.99, H 4.48, N 23.32 Found C 50.00, H 4.50, N 23.39 Example 16 The following compounds were obtained according to a similar manner to that of Example 1. 4-(5-Acetylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)-5-methylthiazole. mp : 247-248°C IR (Nujol) : 3420, 3350, 1660, 1605, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 1.85 (3H, s), 2.40 (3H, s), 4.24 (2H, d, J=5Hz), 6.22 (1H, d, J=3Hz) 6.44 (1H, d, J=3Hz), 6.72 (4H, s), 8.20 (1H, t, J=5Hz) 2-(Diaminomethyleneamino)-4-(5-cyanomethylfuran-2-yl)thiazole. mp : 215-218°C (dec.) IR (Nujol) : 3450, 3420, 3370, 3110, 2250, 2210, 1650, 1610, 1590, 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 4.20 (2H, s), 6.42 (1H, d, J=3Hz), 6.65 (1H, d, J=3Hz), 6.83 (1H, s), 6.87 (4H, s) Example 17 To a solution of 2-(diaminomethyleneamino)-4-(5-cyanomethylfuran-2-yl)thiazole (4.0 g) in dry chloroform (50 ml) and dry methanol (50 ml) was bubbled with dry hydrogen chloride for 100 minutes under ice-cooling and the mixture was stirred for 3.5 hours at the same temperature. The excess hydrogen chloride was removed by reduced pressure under stirring. The resultant mixture was made basic to pH 9.5 with an aqueous potassium carbonate under ice-cooling. The mixture was extracted with the mixture of tetrahydrofuran and ethyl acetate. The extract layer was washed with a brine and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was triturated with ether to give 2-(diaminomethyleneamino)-4-[5-(2-imino-2-methoxyethyl)furan-2-yl]thiazole (4.28 g). mp : 156-162°C (dec.) IR (Nujol) : 3420, 3110, 1655, 1610, 1590, 1550, 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 3.60 (3H, s), 3.65 (2H, s), 6.26 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.73 (1H, s), 6.84 (4H, s), 7.81 (1H, s) Example 18 A mixture of 2-(diaminomethyleneamino)-4-[5-(2-imino-2-methoxyethyl)furan-2-yl]thiazole (4.2 g) and sulfamide (2.9 g) in methanol (100 ml) was heated under reflux for 3 hours. The solvent was removed by concentration in vacuo and to the residue was added a mixture of ethyl acetate and water. The mixture was adjusted to pH 1.0 with 6N-hydrochloric acid and the separated aqueous layer was adjusted to pH 10.0 with 20% aqueous potassium carbonate. The aqueous solution was extracted with a mixture of ethyl acetate and tetrahydrofuran under solution of potassium chloride in aqueous layer. The extract layer was washed with a brine and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was purified by column chromatography on alumina eluting with the mixture of chloroform and methanol (9:1, V/V). The eluted fractions containing the desired product were evaporated to give 4-[5-[2-amino-2-(aminosulfonylimino)ethyl]furan-2-yl]-2-(diaminomethyleneamino)thiazole (0.73 g). mp : 222-225°C (dec.) IR (Nujol) : 3470, 3450, 3400, 3350, 3320, 3230, 1620, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 3.58 (2H, s), 6.28 (1H, d, J=3Hz), 6.52 (2H, s), 6.56 (1H, d, J=3Hz), 6.73 (1H, s), 6.81 (4H, s), 7.35 (1H, s), 8.18 (1H, s) Example 19 A solution of potassium cyanate (1.0 g) in water (9 ml) was dropwise added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (1.5 g) in water (9 ml) and acetic acid (4.5 ml) at 35°C for 2 minutes and the mixture was stirred at the same temperature for 2 hours. To the reaction mixture was added a mixture of ethyl acetate,tetrahydrofuran and water and the resultant mixture was adjusted to pH 9.0 with 20% aqueous potassium carbonate. The separated organic layer was washed with a brine and dried over magnesium sulfate. Evaporation of the solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of ethyl acetate and methanol (85:15, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a aqueous N,N-dimethylformamide to give 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole (0.31 g). mp : 214-215°C IR (Nujol) : 3400, 3320, 3130, 1650, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 4.19 (2H, d, J=5Hz), 5.53 (2H, s), 6.24 (1H, d, J=3Hz), 6.36 (1H, t, J=5Hz), 6.59 (1H, d, J=3Hz), 6.76 (1H, s), 6.87 (4H, s) Anal. Calcd. for C₁₀H₁₂N₆O₂S·1/3 H₂O : C 41.95, H 4.46, N 29.35, H₂O 2.10 Found C 42.04, H 4.53, N 29.04, H₂O 2.33 Example 20 The following compounds were obtained according to a similar manner to that of Example 1. 2-(Diaminomethyleneamino)-4-(5-methoxycarbonylaminomethylfuran-2-yl)thiazole mp : 196°C IR (Nujol) : 3450, 3400, 1710, 1650, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 3.57 (3H, s), 4.19 (2H, d, J=5Hz), 6.26 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.75 (1H, s), 6.85 (4H, s), 7.58 (1H, br s) Anal. Calcd. for C₁₁H₁₃N₅O₃S : C 44.74, H 4.44, N 23.71 Found C 44.71, H 4.63, N 23.83 4-[5-(3-Acetylureidomethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 245°C (dec.) IR (Nujol) : 3400, 3300, 1680, 1650, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 2.02 (3H, s), 4.41 (2H, d, J=6Hz), 6.31 (1H, d, J=3Hz), 6.62 (1H, d, J=3Hz), 6.78 (1H, s), 6.90 (4H, s), 8.68 (1H, t, J=6Hz), 10.43 (1H, s) Anal. Calcd. for C₁₂H₁₄N₆O₃S : C 44.71, H 4.38, N 26.07 Found C 44.53, H 4.24, N 26.24 2-(Diaminomethyleneamino)-4-[5-(6-methyl-5-pentyl-4(1H)-pyrimidinon-2-ylmethyl)furan-2-yl]thiazole. mp : 212-213°C IR (Nujol) : 3450, 1640, 1605, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 0.75-0.95 (3H, m), 1.20-1.50 (6H, m), 2.18 (3H, s), 2.28-2.48 (2H, m), 3.90 (2H, s), 6.31 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.76 (1H, s), 6.90 (1H, s), 12.40 (1H, s) Anal. Calcd. for C₁₉H₂₄N₆O₂S : C 56.98, H 6.04, N 20.98 Found C 56.72, H 5.95, N 20.76 4-(5-Acetylaminomethyl-4-methylfuran-2-yl)-2-(diaminomethyleneamino)thiazole. mp : 237°C IR (Nujol) : 3400, 3280, 3140, 3070, 1640, 1600, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 1.82 (3H, s), 1.99 (3H, s), 4.22 (2H, d, J=5Hz), 6.51 (1H, s), 6.72 (1H, s), 6.88 (4H, s), 8.25 (1H, t, J=5Hz) Anal. Calcd. for C₁₂H₁₅N₅O₂S : C 49.13, H 5.15, N 23.87 Found C 49.48, H 5.15, N 23.93 2-(Diaminomethyleneamino)-4-[5-{2-(methylcarbamoyl)ethyl}furan-2-yl]thiazole. mp : 229 to 230°C IR (Nujol) : 3400, 3340, 1640, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 2.42 (2H, t, J=7.5Hz), 2.59 (3H, d, J=4.5Hz), 2.88 (2H, t, J=7.5Hz), 6.11 (1H, d, J=3.0Hz), 6.52 (1H, d, J=3.0Hz), 6.70 (1H, s), 6.85 (4H, s), 7.79 (1H, d, J=4.5Hz) Anal. Calcd. for C₁₂H₁₅N₅O₂S : C 49.13, H 5.15, N 23.87 Found C 49.08, H 5.32, N 23.67 2-(Diaminomethyleneamino)-4-[5-(3-methylureido)methylfuran-2-yl]thiazole hydrochloride. mp : 220 to 221°C (dec.) IR (Nujol) : 3280, 3140, 1685 cm⁻¹ NMR (DMSO-d₆, δ) : 2.63 (3H, s), 4.30 (2H, d, J=5Hz), 6.00 (1H, br s), 6.32 (1H, d, J=3Hz), 6.45 (1H, t, J=5Hz), 6.80 (1H, d, J=3Hz), 7.07 (1H, s), 8.00 (4H, s) and 12.67 (1H, br s) Example 21 The following compounds were obtained from 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole according to a similar manner to that of Example 3. 4-(5-Butyrylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole. mp : 182 to 183°C IR (Nujol) : 3520, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 0.85 (3H, t, J=7.0Hz), 1.75-1.28 (2H, m), 2.09 (2H, t, J=7Hz), 4.25 (2H, d, J=5.0Hz), 6.24 (1H, d, J=3.3Hz), 6.55 (1H, d, J=3.3Hz), 6.72 (1H, s), 6.83 (4H, s), 8.21 (1H, t, J=5.0Hz) Anal. Calcd. for C₁₃H₁₇N₅O₂S·H₂O : C 47.99, H 5.86, N 21.52 Found C 48.26, H 5.97, N 21.70 2-(Diaminomethyleneamino)-4-(5-valerylaminomethylfuran-2-yl)thiazole. mp : 197°C IR (Nujol) : 3390, 3290, 1650, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 0.80 (3H, t, J=6.3Hz), 1.68-1.00 (4H, m), 2.08 (2H, t, J=6.9Hz), 4.21 (2H, d, J=5.7Hz), 6.18 (1H, d, J=3.0Hz), 6.51 (1H, d, J=3.0Hz), 6.65 (1H, s), 6.79 (4H, s), 8.17 (1H, t, J=5.7Hz) Anal. Calcd. for C₁₄H₁₉N₅O₂S : C 52.30, H 5.96, N 21.79 Found C 52.90, H 6.05, N 22.01 2-(Diaminomethyleneamino)-4-(5-methylthioacetylaminomethylfuran-2-yl)thiazole. mp : 195-197°C (dec.) IR (Nujol) : 3440, 3250, 1620, 1595, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 2.10 (3H, s), 3.10 (2H, s), 4.27 (2H, d, J=5Hz), 6.25 (1H, d, J=3Hz), 6.55 (1H, d, J=3Hz), 6.70 (1H, s), 6.81 (4H, s), 8.37 (1H, t, J=5Hz) Anal. Calcd. for C₁₂H₁₅N₅O₂S : C 44.29, H 4.65, N 21.52 Found C 44.17, H 5.09, N 21.14 2-(Diaminomethyleneamino)-4-[5-(2-nitrobenzoyl)aminomethylfuran-2-yl]thiazole. mp : 218 to 220°C IR (Nujol) : 3420, 3350, 1650, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 4.43 (2H, d, J=5.4Hz), 6.32 (1H, d, J=3.0Hz), 6.55 (1H, d, J=3.0Hz), 6.70 (1H, s), 6.78 (4H, s), 7.99-7.48 (3H, m), 7.97 (1H, dd, J=6.6 and 1.8Hz), 9.09 (1H, t, J=5.4Hz) Anal. Calcd. for C₁₆H₁₄N₆O₄S : C 49.74, H 3.65, N 21.75 Found C 49.37, H 3.76, N 21.57 2-[(Amino) (2-furoylamino)methyleneamino]-4-[5-(2-furoyl)aminomethylfuran-2-yl]thiazole. mp : 199 to 200°C IR (Nujol) : 3450, 3375, 1660, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : =4.47 (2H, d, J=5.3Hz), 6.36 (1H, d, J=3.2Hz), 6.65-6.55 (2H, m), 6.71 (1H, d, J=3.2Hz), 7.12 (1H, s), 7.20-7.05 (1H, m), 7.52 (1H, br), 7.81 (1H, t, J=0.7Hz), 7.94 (1H, s), 8.82 (2H, m) Anal. Calcd. for C₁₉H₁₅N₅O₅S : C 53.64, H 3.55, N 16.46 Found C 53.95, H 3.64, N 16.35 2-(Diaminomethyleneamino)-4-[5-(2-thenoyl)aminomethylfuran-2-yl]thiazole. mp : 217 to 220°C IR (Nujol) : 3400, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 4.41 (2H, d, J=5.4 Hz), 6.26 (1H, d, J=3.0Hz), 6.53 (1H, d, J=3.0Hz), 6.69 (1H, s), 6.78 (4H, s), 7.07 (1H, t, J=4.5Hz), 7.80-7.64 (2H, m), 8.92 (1H, t, J=5.4Hz) Anal. Calcd. for C₁₄H₁₃N₅O₂S₂ : C 48.40, H 3.77, N 20.16 Found C 47.98, H 4.13, N 20.22 2-(Diaminomethyleneamino)-4-(5-mesylaminomethylfuran-2-yl)thiazole. mp : 198°C IR (Nujol) : 3420, 3270, 1650, 1305, 1145 cm⁻¹ NMR (DMSO-d₆, δ) : 2.91 (3H, s), 4.19 (2H, d, J=5.5Hz), 6.37 (1H, d, J=3.5Hz), 6.60 (1H, d, J=3.5Hz), 6.78 (1H, s), 6.85 (4H, s), 7.54 (1H, t, J=5.5Hz) Anal. Calcd. for C₁₀H₁₃N₅O₃S₂ : C 38.08, H 4.16, N 22.21 Found C 37.54, H 4.12, N 21.53 2-(Diaminomethyleneamino)-4-[5-(N,N-dimethylamino)sulfonylaminomethylfuran-2-yl]thiazole. mp : 169°C IR (Nujol) : 3400, 1605, 1520, 1140 cm⁻¹ NMR (DMSO-d₆, δ) : 2.64 (6H, s), 4.13 (2H, d, J=5.8Hz), 6.37 (1H, d, J=3.2Hz), 6.62 (1H, d, J=3.2Hz), 6.79 (1H, s), 6.89 (4H, s), 7.70 (1H, t, J=5.8Hz) Anal. Calcd. for C₁₁H₁₆N₆O₃S₂ : C 38.36, H 4.68, N 24.40 Found C 37.97, H 4.36, N 24.31 Example 22 The following compounds were obtained according to a similar manner to that of Example 5. 2-(Diaminomethyleneamino)-4-[5-(3-ethylureido)methylfuran-2-yl]thiazole. mp : 221-223°C (dec.) IR (Nujol) : 3380, 3300, 1640, 1610, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 1.00 (3H, t, J=7Hz), 2.82-3.20 (2H, m), 4.18 (2H, d, J=6Hz), 5.84 (1H, t, J=6Hz), 6.02-6.33 (1H, m), 6.19 (1H, d, J=3Hz), 6.53 (1H, d, J=3Hz), 6.70 (1H, s), 6.82 (4H, s) Anal. Calcd. for C₁₂H₁₆N₆O₂S : C 46.74, H 5.23, N 27.25 Found C 46.96, H 5.50, N 27.33 2-(Diaminomethyleneamino)-4-[5-(3-n-propylureido)methylfuran-2-yl]thiazole. mp : 223°C IR (Nujol) : 3400, 3330, 3130, 1625, 1595, 1545 cm⁻¹ NMR (DMSO-d₆, δ) : 0.83 (3H, t, J=7Hz), 1.06-1.64 (2H, m), 3.81-3.12 (2H, m), 4.21 (2H, d, J=5Hz), 5.91 (1H, t, J=5Hz), 6.07-6.34 (1H, m), 6.22 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.75 (1H, s), 6.86 (4H, s) Anal. Calcd. for C₁₃H₁₈N₆O₂S : C 48.43, H 5.63, N 26.07 Found C 48.03, H 5.53, N 25.90 4-[5-(3-Allylureido)methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 219-220°C (dec) IR (Nujol) : 3440, 3400, 3325, 1620, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 3.55-3.90 (2H, m), 4.27 (2H, d, J=6Hz), 4.90-5.40 (2H, m), 5.57-6.10 (1H, m), 5.90-6.55 (2H, m), 6.28 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.78 (1H, s), 6.91 (4H, s) Anal. Calcd. for C₁₃H₁₆N₆O₂S : C 48.74, H 5.03, N 26.23 Found C 48.51, H 5.30, N 25.99 2-(Diaminomethyleneamino)-4-[5-{2-(3-methylureido)ethyl}furan-2-yl]thiazole. mp : 224-225°C IR (Nujol) : 3440, 3320, 1660, 1630, 1590, 1540 cm⁻¹ NMR (DSMO-d₆, δ) : 2.52 (3H, d, J=5Hz), 2.70 (2H, t, J=7Hz), 3.05-3.38 (2H, m), 5.57-5.98 (2H, m), 6.13 (1H, d, J=3Hz), 6.51 (1H, d, J=3Hz), 6.70 (1H, s), 6.80 (4H, m) Anal. Calcd. for C₁₂H₁₆N₆O₂S : C 46.74, H 5.23, N 27.25 Found C 46.50, H 4.82, N 27.03 2-(Diaminomethyleneamino)-4-[5-(3-methylthioureido)methylfuran-2-yl]thiazole. mp : 220°C IR (Nujol) : 3400, 3340, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 2.85 (3H, d, J=3.5Hz), 4.64 (2H, d, J=4.5Hz), 6.33 (1H, d, J=3.0Hz), 6.61 (1H, d, J=3.0Hz),6.78 (1H, s), 6.89 (4H, s), 7.50 (1H, br), 7.85 (1H, t, J=4.5Hz) Example 23 The following compounds were obtained according to a similar manner to that of Example 6. 2-(Diaminomethyleneamino)-4-[5-(2-mesyl-3-methylguanidino)methylfuran-2-yl]thiazole hydrochloride. mp : 233 to 234°C IR (Nujol) : 3350, 3230, 1675, 1370, 1100 cm⁻¹ NMR (DMSO-d₆, δ) : 2.76 (3H, d, J=5Hz), 2.80 (3H, s), 4.42 (2H, d, J=6Hz), 6.40 (1H, d, J=3Hz), 6.96 (1H, d, J=3Hz), 7.12 (1H, q, J=5Hz), 7.32 (1H, s), 7.45 (1H, t, J=6Hz) and 8.34 (4H, s) Anal. Calcd. for C₁₂H₁₇N₇O₃S₂·HCl : C 35.34, H 4.45, N 24.04, Cl 8.69 found C 35.11, H 4.59, N 23.88, Cl 8.83 2-(Diaminomethyleneamino)-4-[5-(3-methyl-2-tosylguanidino)methylfuran-2-yl]thiazole. mp : 208 to 209°C IR (Nujol) : 3420, 3380, 3330, 1650, 1375, 1125 cm⁻¹ NMR (DMSO-d₆, δ) : 2.31 (3H, s), 2.71 (3H, d, J=4.5Hz), 4.38 (2H, d, J=5.5Hz), 6.18 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.67 (1H, s), 6.90 (4H, br s), 7.21 (2H, d, J=8Hz), 7.23 (1H, t, J=4.5Hz), 7.54 (1H, t, J=5.5Hz) and 7.61 (2H, d, J=8Hz) Anal. Calcd. for C₁₈H₂₁N₇O₃S₂ : C 48.31, H 4.73, N 21.91 Found C 48.21, H 5.00, N 21.66 Example 24 The following compounds were obtained according to a similar manner to that of Example 11. 2-(Diaminomethyleneamino)-4-[5-(p-methoxyphenylsulfonyl)iminomethylaminomethylfuran-2-yl]thiazole mp : 185 to 186°C IR (Nujol) : 3370, 1620, 1330, 1145 cm⁻¹ NMR (DMSO-d₆, δ) : 3.85 (3H, s), 4.50 (2H, d, J=5Hz), 6.38 (1H, d, J=3Hz), 6.63 (1H, s), 6.65 (1H, d, J=3Hz), 6.97 (4H, s), 7.08 (2H, d, J=9Hz), 7.76 (2H, d, J=9Hz), 8.21 (1H, d, J=5Hz) and 9.08-9.38 (1H, m) Anal. Calcd. for C₁₇H₁₈N₆O₄S₂·H₂O : C 45.12, H 4.45, N 18.57, H₂O 3.98 Found C 45.25, H 4.81, N 18.07, H₂O 2.56 2- Diaminoethyleneamino -4-[5-(p-bromophenylsulfonyl)iminomethylaminomethylfuran-2-yl]thiazole mp : 210 to 211°C IR (Nujol) : 3520, 3400, 1610, 1330, 1140 cm⁻¹ NMR (DMSO-d₆, δ) : 4.55 (2H, d, J=5Hz), 6.42 (1H, d, J=3Hz), 6.65 (1H, s), 6.68 (1H, d, J=3Hz), 6.97 (4H, s), 7.75 (4H, s), 8.25 (1H, d, J=4Hz) and 9.35-9.67 (1H, m) Anal. Calcd. for C₁₆H₁₅BrN₆O₃S₂ : C 39.76, H 3.13, N 17.39 Found C 40.17, H 3.41, N 17.12 2-(Diaminomethyleneamino)-4-(5-mesyliminomethylaminomethylfuran-2-yl)thiazole. mp : 222 to 223°C (dec.) IR (Nujol) : 3440, 3360, 3290, 1600, 1320, 1120 cm⁻¹ NMR (DMSO-d₆, δ) : 2.90 (3H, s), 4.48 (2H, d, J=5.4Hz), 6.41 (1H, d, J=3.0Hz), 6.62 (1H, d, J=3.0Hz), 6.80 (1H, s), 6.85 (4H, s), 8.03 (1H, d, J=4.5Hz) and 9.09 (1H, br s) Anal. Calcd. for C₁₁H₁₄N₆O₃S₂ C 38.59, H 4.12, N 24.54 Found C 38.66, H 4.24, N 24.85 2-(Diaminomethyleneamino)-4-(5-ethylsulfonyliminomethylaminomethylfuran-2-yl)thiazole. mp : 188°C IR (Nujol) : 3460, 3400, 3350, 1630, 1320, 1130 cm⁻¹ NMR (DMSO-d₆, δ) : 1.13 (2.64 H, t, J=7.5Hz), 1.14 (0.36H, t, J=7.5Hz), 2.96 (2H, q, J=7.5Hz), 4.48 (1.76H, d, J=5.0 Hz), 4.54 (0.24 H, d, J=5.5Hz), 6.42 (1H, d, J=3.0Hz), 6.65 (1H, d, J=3.0Hz), 6.78 (0.12H, s), 6.80 (0.88H, s), 6.89 (4H, s), 8.00 (0.88H, d, J=4.5Hz), 8.18 (0.12H, d, J=13.0Hz), 9.14 (0.88H, dd, J=5.0 and 4.5Hz), 9.4-9.2 (0.12H, br) Anal. Calcd. for C₁₂H₁₆N₆O₃S₂ : C 40.44, H 4.52, N 23.58 Found C 40.49, H 4.53, N 23.46 4-(5-Cyanoiminomethylaminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole. mp : 193 to 194°C IR (Nujol) : 3400, 3190, 2170, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.52 (2H, s), 6.59 (1H, d, J=3Hz), 6.68 (1H, d, J=3Hz), 6.83 (1H, s), 6.92 (4H, s), 8.42 (1H, s) and 9.50 (1H, br s) Anal. Calcd. for C₁₁H₁₁N₇OS : C 45.67, H 3.83, N 33.89 Found C 45.61, H 4.53, N 33.49 4-[5-(1-Cyanoiminoethyl)aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole mp : 215 to 217°C IR (Nujol) : 3320, 3180, 2180, 1600, 1570, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 2.25 (3H, s), 4.42 (2H, d, J=4Hz), 6.43 (1H, s), 6.64 (1H, s), 6.81 (1H, s), 6.90 (4H, s), 9.28 (1H, s) Anal. Calcd. for C₁₂H₁₃N₇OS : C 47.53, H 4.32, N 32.32 Found C 47.48, H 4.33, N 31.95 Example 25 The following compounds were obtained according to a similar manner to that of Example 18. 4-[5-(2-Amino-2-mesyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 168 to 169°C (dec.) IR (Nujol) : 3460, 3400, 3350, 3240, 3170, 3120, 1660, 1640, 1620, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 2.88 (3H, s), 3.69 (2H, s), 6.32 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.77 (1H, s), 6.86 (4H, s), 7.83 (1H, s), 8.50 (1H, s) Anal. Calcd. for C₁₁H₁₄N₆O₃S₂·H₂O C 36.66, H 4.47, N 23.32, H₂O 5.00 Found C 36.80, H 4.31, N 23.44, H₂O 5.22 4-[5-{2-Amino-2-(p-aminophenylsulfonyl)iminoethyl}furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 190-191°C (dec.) IR (Nujol) : 3400, 3340, 1635, 1600, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 3.63 (2H, s), 5.81 (2H, s), 6.19 (1H, d, J=3Hz), 6.55 (2H, d, J=8Hz), 6.58 (1H, d, J=3Hz), 6.70 (1H, s), 6.87 (4H, s), 7.45 (2H, d, J=8Hz), 7.85 (1H, s), 8.47 (1H, s) Anal. Calcd. for C₁₆H₁₇N₇O₃S₂ : C 45.81, H 4.08, N 23,37 Found C 45.92, H 4.21, N 22.95 4-[5-(2-Amino-2-tosyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 207-209°C (dec.) IR (Nujol) : 3450, 3420, 3380, 3320, 1670, 1630, 1605, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 2.33 (3H, s), 3.68 (2H, s), 6.20 (1H, d, J=3Hz), 6.57 (1H, d, J=3Hz), 6.64 (1H, s), 6.90 (4H, s), 7.26 (2H, d, J=8Hz), 7.67 (2H, d, J=8Hz), 8.10 (1H, s), 8.76 (1H, s) Anal. Calcd. for C₁₇H₁₈N₆O₃S₂ : C 48.79, H 4.34, N 20.08 Found C 48.44, H 4.19, N 19.77 4-[5-(2-Amino-2-methylaminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 219 to 220°C (dec.) IR (Nujol) : 3480, 3430, 3380, 3330, 1610, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 2.42 (3H, d, J=5Hz), 3.65 (2H, s), 6.32 (1H, d, J=3Hz), 6.59 (1H, q, J=5Hz), 6.62 (1H, d, J=3Hz), 6.75 (1H, s), 6.89 (4H, s), 7.63 (1H, s), 8.42 (1H, s) Anal. Calcd. for C₁₁H₁₅N₇O₃S₂ : C 36.97, H 4.23, N 27.43 Found C 36.93, H 4.15, N 27.41 4-[5-{2-Amino-2-(N,N-dimethylamino)sulfonyliminoethyl}furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 161°C IR (Nujol) : 3460, 3340, 1660, 1630, 1565, 1515 cm⁻¹ NMR (DMSO-d₆, δ) : 2.51 (6H, s), 3.69 (2H, s), 6.33 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.75 (1H, s), 6.89 (4H, s), 7.81 (1H, s), 8.51 (1H, s) Anal. Calcd. for C₁₂H₁₇N₇O₃S₂ : C 38.80, H 4.61, N 26.40 Found C 38.62, H 4.39, N 26.42 Example 26 2-Furoyl chloride (0.48 g) was added slowly to a solution of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.80 g) in N,N-dimethylformamide (20 ml) with cooling on an ice bath and the mixture was stirred for an hour with cooling on an ice bath. The solvent was removed under reduced pressure and the residue was chromatographed on a silica gel column eluting with a mixture of chloroform and methanol (30:1, V/V). Recrystallization from methanol afforded 2-(diaminomethyleneamino)-4-[5-(2-furoyl)aminomethylfuran-2-yl]thiazole (0.20 g). mp : 246°C IR (Nujol) : 3400, 1655, 1625, 1600 cm⁻¹ NMR (DMSO-d₆, δ) : 4.42 (2H, d, J=5.5Hz), 6.26 (1H, d, J=3.8Hz), 6.64-6.40 (2H, m), 6.72 (1H, s), 6.83 (4H, s), 7.11 (1H, dd, J=1.0 and 3.8Hz), 7.77 (1H, m), 8.78 (1H, t, J=5.5Hz) Anal. Calcd. for C₁₄H₁₃N₅O₃S : C 50.75, H 3.95, N 21.14 Found C 50.69, H 3.81, N 21.01 Example 27 Dicyclohexylcarbodiimide (2.3 g) was added slowly to a suspension of nicotinic acidN-oxide (1.5 g) in N,N-dimethylformamide (40 ml) with cooling on an ice bath and the mixture was stirred for 15 minutes with cooling on an ice bath. To the mixture 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (2.0 g) was added with cooling on an ice bath. The mixture was stirred for an hour in cooling on an ice bath and then stirred for 41 hours at room temperature. The solvent was removed under reduced pressure and the residue was suspended in water. 6N-Hydrochloric acid solution was added to the suspension and the resulting precipitate was removed by filtration. The solvent was removed under reduced pressure and the residue was dissolved in methanol. The insoluble material was removed by filtration and the solvent was removed under reduced pressure. The residue was chromatographed on a silica gel column eluting with a mixture of chloroform and methanol (10:1, V/V). Recrystallization from a mixture of methanol, dioxane and diisopropyl ether afforded 2-(diaminomethyleneamino)-4-[5-(1-oxonicotinoylaminomethyl)furan-2-yl]thiazole (0.30 g). mp : 217°C IR (Nujol) : 3420, 1670, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 4.51 (2H, d, J=5.5Hz), 6.39 (1H, d, J=3.2Hz), 6.63 (1H, d, J=3.2Hz), 6.78 (1H, s), 6.90 (4H, s), 7.52 (1H, dd, J=6.4 and 8.0Hz), 7.76 (1H, d, J=8.0Hz), 8.37 (1H, d, J=6.4Hz), 8.62 (1H, s), (9.31 (1H, t, J=5.5Hz), Anal. Calcd. for C₁₅H₁₄N₆O₃S·3/4H₂O : C 48.45, H 4.20, N 22.59 Found C 48.79, H 4.03, N 22.22 Example 28 A mixture of 4-(5-acetylaminomethylfuran-2-yl)-2-thioureidothiazole (1.50 g) and methyl iodide (0.32 ml) in methanol (30 ml) and tetrahydrofuran (15 ml) was refluxed for 5 hours with stirring. After the solvent was evaporated in vacuo to give 2-[(amino)(methylthio)methyleneamino]-4-(5-acetylaminomethylfuran-2-yl)thiazole, the residue was mixed with ethylenediamine (0.91 g) and ethanol (30 ml) and the mixture was refluxed for 18 hours. After cooling, the resulting precipitate was collected by filtration and mixed with water (30 ml). The suspension was acidified to pH 2 with 6N hydrochloric acid, and then made basic to pH 11 with an aqueous potassium carbonate. The resulting precipitate was collected, washed with water and recrystallized from a mixture of methanol and tetrahydrofuran to afford 4-(5-acetylaminomethylfuran-2-yl)-2-(imidazolidin-2-ylideneamino)thiazole (0.51 g). mp : 239 to 240°C IR (Nujol) : 3290, 3105, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 1.88 (3H, s), 3.57 (4H, s), 4.33 (2H, d, J=6Hz), 6.33 (1H, d, J=3Hz), 6.82 (1H, s), 6.85 (1H, d, J=3Hz), 7.68 (2H, s) and 8.33 (1H, t, J=6Hz) Anal. Calcd. for C₁₃H₁₅N₅O₂S : C 51.13, H 4.95, N 22.93 Found C 50.91, H 4.62, N 22.85 Example 29 A suspension of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (1.6 g) and sulfamide (1.0 g) in ethylene glycol dimethyl ether (30 ml) was refluxed for 24 hours. The solvent was removed under reduced pressure and the residue was chromatographed on an alumina column eluting with a mixture of chloroform and methanol (4:1, V/V). Recrystallization from a mixture of methanol, ethyl acetate and diisopropyl ether afforded 2-(diaminomethyleneamino)-4-(5-sulfamoylaminomethylfuran-2-yl)thiazole (1.16 g). mp : 175 to 177°C (dec.) IR (Nujol) : 3400, 3360, 1650, 1530, 1140 cm⁻¹ NMR (DMSO-d₆, δ) : 4.01 (2H, d, J=6.1Hz), 6.38 (1H, d, J=3.2z), 6.62 (1H, d, J=3.2Hz), 6.67 (2H, s), 6.83 (1H, s), 6.96 (4H, s), 7.07 (1H, t, J=6.1Hz) Anal. Calcd. for C₉H₁₂N₆O₃S₂ : C 34.17, H 3.82, N 26.57 Found C 33.92, H 3.79, N 26.55 Example 30 A mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (2.50 g) and dimethyl N-cyanodithioiminocarbonate (1.54 g) in ethanol (25 ml) was refluxed for two hours with stirring. After the solvent was evaporated in vacuo, the residue was chromatographed on alumina eluting with a mixture of chloroform and methanol (20:1, V/V), followed by recrystallization from a mixture of methanol, tetrahydrofuran and diisopropyl ether to afford 2-(diaminomethyleneamino)-4-[5-(3-cyano-2-methylisothioureido)methylfuran-2-yl]thiazole (1.48 g). mp : 210°C (dec.) IR (Nujol) : 3450, 3300, 3270, 2165, 1655 cm⁻¹ NMR (DMS0-d₆, δ) : 2.59 (3H, s), 4.48 (3H, s), 6.33 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.73 (1H, s), 6.83 (4H, s) and 8.82 (1H, br s) Anal. Calcd. for C₁₂H₁₃N₇OS₂ : C 42.97, H 3.91, N 29.23 Found C 43.08, H 3.65, N 29.38 Example 31 A mixture of 2-(diaminomethyleneamino)-4-[5-(3-cyano-2-methyl-1-isothioureido)methylfuran-2-yl]thiazole (1.35 g) and 28% methanolic sodium methoxide by weight (0.78 g) in methanol was refluxed for one hour with stirring. After the solvent was evaporated in vacuo, the residue was mixed with water (5 ml) and the medium was adjusted to pH 9 with 6N-hydrochloric acid. The insoluble material was collected by filtration, washed with water and recrystallized from aqueous N,N-dimethylformamide to afford 4-[5-(3-cyano-2-methyl-1-isoureido)methylfuran-2-yl)]-2-(diaminomethyleneamino)thiazole (0.82 g). mp : 205 to 206°C IR (Nujol) : 3460, 3345, 2180, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 3.83 (3H, s), 4.33 (2H, s), 6.33 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.74 (1H, s), 6.87 (4H, s) and 8.50 (1H, br s) Anal. Calcd. for C₁₂H₁₃N₇O₂S : C 45.13, H 4.10, N 30.70 Found C 44.93, H 4.33, N 30.42 Example 32 A mixture of 2-(diaminomethyleneamino)-4-[5-(3-cyano-2-methyl-1-isothioureido)methylfuran-2-yl]thiazole (1.10 g) and monoethanolamine (1 ml) in N,N-dimethylformamide (10 ml) was stirred at 70°C for 7 hours. The solvent was evaporated in vacuo and the residue was mixed with water. The resulting precipitate was collected by filtration, washed with water and recrystallized from a mixture of dioxane, methanol and diisopropyl ether to afford 4-[5-{2-cyano-3-(2-hydroxyethyl)guanidino}methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole (0.80 g). mp : 208 to 209°C IR (Nujol) : 3500, 3390, 3350, 3300, 2160, 1610 cm⁻¹ NMR (DMSO-d₆, δ) : 3.23-3.52 (4H, m), 4.40 (2H, d, J=5Hz), 4.92 (1H, t, J=4Hz), 6.34 (1H, d, (J=3Hz), 6.62 (1H, d, J=3Hz), 6.80 (1H, s), 6.90 (4H, s) and 7.52 (1H, t, J=5Hz) Anal. Calcd. for C₁₃H₁₆N₈O₂S : C 44.82, H 4.63, N 32.16 Found C 45.12, H 4.91, N 32.10 Example 33 A solution of trifluoroacetic acid (24.9 ml) in tetrahydrofuran (50 ml) was dropwise added to a mixture of sodium borohydride (12.2 g) in tetrahydrofuran (100 ml) for an hour under ice-cooling and the mixture was stirred for 30 minutes at the same temperature. To this mixture was dropwise added a mixture of 4-(5-cyanomethylfuran-2-yl)-2-(diaminomethyleneamino) thiazole (16.0 g) in tetrahydrofuran (30 ml) for 30 minutes under ice cooling and the mixture was stirred for an hour at ambient temperature. The reaction mixture was added to a mixture of ethyl acetate and water and the mixture was adjusted to pH 1 with 6N-hydrochloric acid. The separated aqueous layer was adjusted to pH 10 with 10% aqueous sodium hydroxide and the mixture was extracted with a mixture of tetrahydrofuran and ethyl acetate. The extract layer was washed with brine and dried over magnesium sulfate. The solvent was concentrated to give 4-[5-(2-aminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole (4.71 g). mp : 156-158°C IR (Nujol) : 3400, 1660, 1590, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 2.57-3.00 (4H, m), 6.16 (1H, d, J=3Hz), 6.53 (1H, d, J=3Hz), 6.71 (1H, s), 6.88 (4H, s) Example 34 A mixture of 2-[(amino)(methylthio)methyleneamino]-[4-(5-cyanomethylfuran-2-yl)thiazole hydriodide (6.0 g) and 2,2,2-trifluoroethylamine (3.5 ml) in ethanol (120 ml) was refluxed for 18 hours. The solvent was removed by concentration and a residue was added to a mixture of water, ethyl acetate and tetrahydrofuran. The mixture was adjusted to pH 10.0 with potassium carbonate and a separated organic layer was washed with brine, dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (19:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo to give 2-[(amino){(2,2,2-trifluoroethyl)amino}methyleneamino]-4-(5-cyanomethylfuran-2-yl)thiazole (2.41 g). mp : 152 to 153°C IR (Nujol) : 3450, 3400, 2260, 1630, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 4.02-4.15 (2H, m), 4.23 (2H, s), 6.47 (1H, d, J=3Hz), 6.72 (1H, d, J=7Hz), 6.87 (1H, s), 7.14 (1H, br s), 7.77 (2H, br s) Example 35 The following compounds were obtained according to a similar manner to that of Example 34. 2-[(Amino){(2,2,2-trifluoroethyl)amino}methyleneamino]-4-[5-(3-methylureido)methylfuran-2-yl]thiazole. mp : 170 to 171°C IR (Nujol) : 3375, 3330, 1630, 1570, 1545 cm⁻¹ NMR (DMSO-d₆, δ) : 2.57 (3H, d, J=5Hz), 4.00-4.23 (2H, m) 4.22 (2H, d, J=6Hz), 5.82 (1H, q, J=5Hz), 6.25 (1H, d, J=3Hz), 6.35 (1H, t, J=6Hz), 6.63 (1H, d, J=3Hz), 6.87 (1H, s), 7.12 (1H, br s), 7.75 (1H, br s) Anal. Calcd. for C₁₃H₁₅N₆O₂SF₃·1/5H₂O : C 41.00, H 4.10, N 22.07 Found C 41.11, H 3.95, N 21.67 2-[(Amino)(methylamino)methyleneamino]-4-(5-ureidomethylfuran-2-yl)thiazole. mp : 210 to 211°C IR (Nujol) : 3490, 3400, 3340, 3300, 3110, 1640, 1595 cm⁻¹ NMR (DMSO-d₆, δ) : 2.73 (3H, d, J=5Hz), 4.18 (2H, d, J=5Hz), 5.52 (2H, s), 6.23 (1H, d, J=3Hz), 6.35 (1H, t, J=5Hz), 6.57 (1H, d, J=3Hz), 6.87-7.18 (1H, m) 7.39 (2H, s) Anal. Calcd. for C₁₁H₁₄N₆O₂S : C 44.89, H 4.79, N 28.55 Found C 45.05, H 4.79, N 28.20 2-[(Amino){(2,2,2-trifluoroethyl)amino}methyleneamino]-4-(5-ureidomethylfuran-2-yl)thiazole. mp : 198 to 200°C IR (Nujol) : 3400, 3300, 1635, 1570, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 4.01-4.20 (2H, m), 4.19 (2H, d, J=6Hz), 5.56 (2H, s), 6.26 (1H, d, J=3Hz), 6.38 (1H, t, J=6Hz), 6.64 (1H, d, J=3Hz), 6.88 (1H, s), 7.13 (1H, s), 7.75 (2H, s) Anal. Calcd. for C₁₂H₁₃N₆O₂SF₃ : C 39.78, H 3.62, N 23.19 Found C 39.93, H 3.71, N 23.15 Example 36 The following compound was obtained according to a similar manner to that of the latter half of Example 28. 2-(Imidazolidin-2-ylideneamino)-4-(5-ureidomethylfuran-2-yl)thiazole. mp : 245 to 247°C (dec.) IR (Nujol : 3430, 3375, 3310, 1650, 1625, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 3.53 (4H, s), 4.21 (2H, d, J=5Hz), 5.60 (2H, s), 6.27 (1H, s), 6.41 (1H, t, J=5Hz), 6.78 (1H, s), 6.82 (1H, s), 7.57 (2H, s) Anal. Calcd. for C₁₂H₁₄N₆O₂S : C 47.05, H 4.61, N 27.43 Found C 46.91, H 4.69, N 26.99 Example 37 An ice-cooled mixture of 4-(5-cyanomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (30.0 g) in dry methanol (250 ml) and chloroform (250 ml) was bubbled with hydrogen chloride for 2 hours and the mixture was stirred for 3 hours under ice-cooling. To a mixture was added a diisopropyl ether (300 ml) and the isolated precipitate was collected by filtration. To a precipitate was added a solution of methanol (100 ml) and water (200 ml) and a mixture was stirred for 30 minutes at ambient temperature. The mixture was adjusted to pH 9.5 with potassium carbonate and the mixture was extracted with a mixture of tetrahydrofuran and ethyl acetate. The extract layer was washed with a brine and dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was triturated with diisopropyl ether to give 2-(diaminomethyleneamino)-4-(5-methoxycarbonylmethylfuran-2-yl)thiazole (24.4 g). mp : 187 to 193°C IR (Nujol) : 3450, 3350, 3120, 1730, 1660, 1600, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 3.65 (3H, s), 3.83 (2H, s), 6.35 (1H, d, J=3Hz), 6.62 (1H, d, J=3Hz), 6.77 (1H, s), 6.91 (4H, s) Example 38 An ice-cooled solution of 2-(diaminomethyleneamino)-4-(5-methoxycarbonylmethylfuran-2-yl)thiazole (1.0 g) in methanol (20 ml) was bubbled with ammonia for 30 minutes and a mixture was stirred at ambient temperature for 25 hours. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of chloroform and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a mixture of ethanol, dioxane and diisopropyl ether to give 4-(5-carbamoylmethylfuran-2-yl)-2-diaminomethyleneamino)thiazole (0.44 g). mp : 219 to 220°C IR (Nujol) : 3360, 3160, 3110, 1650, 1600, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 3.51 (2H, s), 6.25 (1H, d, J=3Hz), 6.58 (1H, d, J=3Hz), 6.73 (1H, s), 6.87 (4H, s), 6.95 (1H, br s), 7.40 (1H, br s) Mass : m/e 265 (M⁺) Anal. Calcd. for C₁₀H₁₁N₅O₂S C 45.28, H 4.18, N 26.40 Found C 44.77, H 4.13, N 26.23 Example 39 A solution of 4N-hydrogenchloride in 1,4-dioxane (2.2 ml) was added to a mixture of 4-[5-(2-amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole (3.0 g) in methanol (60 ml) and the mixture was stirred at ambient temperature for 4 hours. To a mixture was added a diisopropyl ether (30 ml) and the isolated precipitate was collected by filtration. The precipitate was recrystallized from an aqueous ethanol to give 4-[5-(2-amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole hydrochloride (2.17 g). mp : 219 to 221°C IR (Nujol) : 3380, 3340, 1680, 1640, 1615, 1550, 1505 cm⁻¹ NMR (DMSO-d₆, δ) : 3.63 (2H, s), 6.38 (1H, d, J=3Hz), 6.54 (1H, br s), 6.94 (1H, d, J=3Hz), 7.20 (1H, s), 7.31 (1H, s), 8.32 (5H, br s) Anal. Calcd. for C₁₀H₁₃N₇O₃S₂·HCl C 31.62, H 3.71, N 25.81, Cl 9.33 Found C 31.02, H 3.71, N 25.53, Cl 9.43 Example 40 A mixture of 2-(diaminomethyleneamino)-4-[5-(3-cyano-2-methyl-1-isothioureido)methylfuran-2-yl]thiazole (0.80 g) and hydrazine hydrate (1.2 g) in ethanol (10 ml) was stirred at ambient temperature for two hours. After cooling, the resulting precipitate was collected by filtration and recrystallized from aqueous N,N-dimethylformamide to afford 4-[5-{(3-amino-1H-1,2,4-triazol-5-yl)aminomethyl}furan-2-yl]-2-(diaminomethyleneamino)thiazole (0.52 g). mp : 241 to 242°C IR (Nujol) : 3570, 3470, 3360, 3295, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.23 (2H, d, J=6Hz), 5.34 (2H, br s), 5.93 (1H, br s), 6.23 (1H, d, J=3Hz), 6.55 (1H, d, J=3Hz), 6.73 (1H, s), and 6.85 (4H, br s) Anal. Calcd. for C₁₁H₁₃N₉OS·H₂O : C 39.16, H 4.48, N 37.37, H₂O 5.34 Found C 38.94, H 4.30, N 37.30, H₂O 5.70 Example 41 A solution of 2-(diaminomethyleneamino)-4-(5-methoxycarbonylfuran-2-yl)thiazole (5.00 g) and hydrazine hydrate (9.40 g) in ethanol (50 ml) was refluxed for 4 hours with stirring. The mixture was cooled and the resulting precipitate was collected by filtration to afford 2-(diaminomethyleneamino)-4-(5-hydrazinocarbonylfuran-2-yl)thiazole (4.86 g). mp : 279 to 280°C IR (Nujol) : 3400, 3360, 3320, 3250, 3175, 3125, 1660, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.53 (2H, br s), 6.85 (1H, d, J=3Hz), 6.98 (4H, br s), 7.18 (1H, d, J=3Hz), 7.27 (1H, s) and 9.77 (1H, br s) Example 42 A solution of 2-(diaminomethyleneamino)-4-(5-hydrazinocarbonylfuran-2-yl)thiazole (1.50 g) and S-methylisothiourea hemisulfate (1.57 g) in dimethyl sulfoxide (12 ml) was heated at 180°C for two hours with stirring. After cooling, the resulting precipitate was collected by filtration and washed with dimethyl sulfoxide followed by washing with isopropyl alcohol and diisopropyl ether to afford 2-(diaminomethyleneamino)-4-(5-guanidinocarbamoylfuran-2-yl)thiazole sulfate (1.83 g). mp : >300°C IR (Nujol) : 3325, 3150, 3110, 1690, 1670 cm⁻¹ Anal. Calcd. for C₁₀H₁₂N₈O₂S·H₂SO₄ : C 29.55, H 3.47, N 27.57 Found C 28.07, H 3.72, N 28.22 Example 43 A suspension of 2-(diaminomethyleneamino)-4-(5-guanidinocarbamoylfuran-2-yl)thiazole sulfate (1.70 g) in concentrated ammonium hydroxide (17 ml) was refluxed with stirring. Additional ammonium hydroxide (8.5 ml) was added twice. After refluxing for 8 hours, water was added to the mixture and the resulting precipitate was collected by filtration, followed by recrystallization from aqueous N,N-dimethylformamide to afford 4-[5-(3-amino-1H-1,2,4-triazol-5-yl)furan-2-yl]-2-(diaminomethyleneamino)thiazole (0.73 g). mp : >300°C IR (Nujol) : 3440, 3400, 3330, 3120, 1670, 1640 cm⁻¹ NMR (DMSO-d₆, δ) : 6.00 (2H, s), 6.76 (2H, s), 6.87 (1H, s), 6.92 (4H, s) Anal. Calcd. for C₁₀H₁₀N₈OS·1/4H₂O C 40.74, H 3.59, N 38.17, H₂O 1.53 Found C 40.48, H 3.55, N 37.61, H₂O 1.25 Example 44 The following compounds were obtained according to a similar manner to that of Example 30. 2-(Diaminomethyleneamino)-4-[5-(3-mesyl-2-methyl-1-isothioureido)methylfuran-2-yl]thiazole. mp : 210 to 211°C IR (Nujol) : 3420, 3320, 1655, 1350, 1120 cm⁻¹ NMR (DMSO-d₆, δ) : 2.53 (3H, s), 3.00 (3H, s), 4.58 (2H, s), 6.45 (1H, d, J=3Hz), 6.72 (1H, d, J=3Hz), 6.85 (1H, s), 6.95 (4H, s) and 8.50 (1H, br s) Anal. Calcd. for C₁₂H₁₆N₆O₃S₂ C 37.10, H 4.15, N 21.63 Found C 37.42, H 4.36, N 21.76 2-(Diaminomethyleneamino)-4-[5-{N-(1-methylthio-2-nitrovinyl)aminomethyl}furan-2-yl]thiazole. mp: 214°C (dec.) IR (Nujol) : 3350, 1660, 1610, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 2.45 (3H, s), 4.65 (2H, d, J=5.4Hz), 6.38 (1H, d, J=3.6Hz), 6.65-6.57 (2H, m), 6.72 (1H, s), 6.76 (4H, s), 10.55 (1H, br) Example 45 The following compounds were obtained according to a similar manner to that of Example 32. 4-[5-(3-Allyl-2-cyanoguanidino)methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 164 to 165°C IR (Nujol) : 3425, 3240, 2160, 1645 cm⁻¹ NMR (DMSO-d₆, δ) : 3.78 (2H, t, J=6Hz), 4.36 (2H, d, J=6Hz), 5.01 (1H, d, J=1.5Hz), 5.16 (1H, dd, J=1.5Hz and 8Hz), 5.62-6.03 (1H, m), 6.28 (1H, d, J=3Hz), 6.61 (1H, d, J=3Hz), 6.74 (1H, s), 6.86 (4H, s) and 7.14-7.46 (2H, m) Anal. Calcd. for C₁₄H₁₆N₈OS : C 48.83, H 4.68, N 32.54 Found C 48.86, H 4.41, N 32.58 4-[5-(2-Cyano-3,3-dimethylguanidino)methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 205 to 206°C IR (Nujol) : 3350, 2160, 1650 cm⁻¹ NMR (DMSO-d₆, δ) : 2.99 (6H, s), 4.51 (2H, d, J=5.6Hz), 6.36 (1H, d, J=3.2Hz), 6.63 (1H, d, J=3.2Hz), 6.78 (1H, s), 6.91 (4H, s), 7.54 (1H, t, J=5.6Hz) Anal. Calcd. for C₁₃H₁₆N₈OS C 46.98, H 4.85, N 33.71 Found C 47.14, H 4.92, N 33.66 4-[5-{N-(1-n-Butylamino-2-nitrovinyl)aminomethyl}furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 215 to 217°C IR (Nujol) : 3360, 1610, 1550, 1370 cm⁻¹ NMR (DMSO-d₆, δ) : 0.89 (3H, t, J=7.2Hz), 1.53-1.27 (2H, m), 2.52-2.48 (2H, m), 3.22 (2H, br), 4.43 (2H, br), 6.41 (1H, d, J=3.2Hz), 6.65-6.64 (2H, m), 6.76 (1H, s), 6.89 (4H, s), 7.75 (1H, br), 10.17 (1H, br) Anal. Calcd. for C₁₅H₂₁N₇O₃S C 47.48, H 5.58, N 25.84 Found C 47.44, H 5.71, N 25.97 2-(Diaminomethyleneamino)-4-[5-[N-{1-(2-hydroxyethyl)amino-2-nitrovinyl}aminomethyl]furan-2-yl]thiazole. mp : 182 to 183°C (dec.) IR (Nujol) : 3330, 1610, 1550, 1380 cm⁻¹ NMR (DMSO-d₆, δ) : 3.65-3.00 (4H, m), 4.34 (2H, d, J=4.8Hz), 5.10-4.60 (1H, br), 6.29 (1H, d, J=3.0Hz), 6.52 (2H, s), 6.67 (1H, s), 6.75 (4H, s), 7.90-7.30 (1H, br), 10.30-9.30 (1H, br) Anal. Calcd. for C₁₃H₁₇N₇O₄S·3/4H₂O : C 40.99, H 4.90, N 25.74 Found C 41.04, H 5.13, N 26.04 2-(Diaminomethyleneamino)-4-[5-{3-(2-hydroxyethyl)-2-mesylguanidino}methylfuran-2-yl]thiazole. mp : 202 to 203°C IR (Nujol) : 3570, 3410, 3340, 3220, 3120, 1610, 1375, 1360, 1340, 1100 cm⁻¹ NMR (DMSO-d₆, δ) : 2.80 (3H, s), 3.14-3.26 (2H, m), 3.43-3.60 (2H, m), 4.39 (2H, d, J=6Hz) 4.91 (1H, t, J=5Hz), 6.34 (1H, d, J=3Hz), 6.62 (1H, d, J=3Hz), 6.78 (1H, s), 6.86 (4H, s), 7.21 (1H, t, J=5Hz) and 7.49 (1H, t, J=6Hz) Anal. Calcd. for C₁₃H₁₉N₇O₄S₂ : C 38.89, H 4.77, N 24.42 Found C 38.89, H 5.20, N 24.22 2-(Diaminomethyleneamino)-4-[5-{2-mesyl-3-(2-methoxyethyl)guanidino}methylfuran-2-yl]thiazole. mp : 173 to 174°C IR (Nujol) : 3430, 3400, 3340, 1360, 1110 cm⁻¹ NMR (DMSO-d₆, δ) : 2.77 (3H, s), 3.23 (3H, s), 3.30-3.47 (4H, m), 4.39 (2H, d, J=6Hz), 6.31 (1H, d, J=3Hz), 6.60 (1H, d, J=3Hz), 6.75 (1H, s), 6.87 (4H, s), 7.20 (1H, t, J=6Hz) and 7.49 (1H, t, J=6Hz) Anal. Calcd. for C₁₄H₂₁N₇O₄S₂ : C 40.47, H 5.09, N 23.60 Found C 40.56, H 4.94, N 23.64 2-(Diaminomethyleneamino)-4-[5-(3-ethyl-2-mesylguanidino)methylfuran-2-yl]thiazole. mp : 151 to 152°C IR (Nujol) : 3380, 3230, 1680, 1650, 1340, 1160 cm⁻¹ NMR (DMSO-d₆, δ) : 1.09 (3H, t, J=7Hz), 2.78 (3H, s), 3.13-3.26 (2H, m), 4.43 (2H, d, J=5Hz), 6.40 (1H, d, J=3Hz), 7.00 (1H, d, J=3Hz), 7.18 (1H, br s), 7.30 (1H, s), 7.75 (1H, br s), 8.37 (4H, s) and 12.80 (1H, br s) Anal. Calcd. for C₁₃H₁₉N₇O₃S₂·2HCl·1/3H₂O C 33.62, H 4.70, N 21.11, Cl 15.27, H₂O 1.29 Found C 33.75, H 4.53, N 21.05, Cl 15.06, H₂O 1.18 2-(Diaminomethyleneamino)-4-[5-{3-(2-dimethylaminoethyl)-2-mesylguanidino}methylfuran-2-yl]thiazole. mp : 183 to 184°C IR (Nujol) : 3450, 3410, 3340, 1650, 1650, 1330, 1110 cm⁻¹ NMR (DMSO-d₆, δ) : 2.13 (6H, s), 2.37 (2H, t, J=6Hz), 2.78 (3H, s), 3.19-3.27 (2H, m), 4.37 (2H, d, J=5Hz), 6.36 (1H, d, J=3Hz), 6.63 (1H, d, J=3Hz), 6.78 (1H, s), 6.90 (4H, br s), 6.90 (1H, t, J=5Hz) and 8.14 (1H, br s) Anal. Calcd. For C₁₅H₂₄N₈O₃S₂ : C 42.04, H 5.64, N 26.15 Found C 42.32, H 5.61, N 26.31 4-[5-{2-Cyano-3-(3-hydroxypropyl)guanidino}methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 160 to 161°C IR (Nujol) : 3350, 2040, 1650 cm⁻¹ NMR (DMSO-d₆, δ) : 1.56-1.69 (2H, m), 3.20 (2H, q, J=6Hz), 3.43 (2H, q, J=5Hz), 4.35 (2H, d, J=5.5Hz), 4.53 (1H, t, J=5Hz), 6.30 (1H, d, J=3Hz), 6.62 (1H, d, J=3Hz), 6.76 (1H, s), 6.90 (4H, br s), 7.09 (1H, t, J=5.5Hz) and 7.47 (1H, t, J=6Hz) Example 46 The following compound was obtained according to similar manners to those of Example 30 and Example 32, continuously. 2-(Diaminomethyleneamino)-4-[5-{N-(2-nitro-1-propargylaminovinyl)aminomethyl}furan-2-yl]thiazole. mp : 199 to 200°C (dec.) IR (Nujol) : 3430, 1620, 1560, 1370 cm⁻¹ NMR (DMSO-d₆, δ) : 3.38-3.30 (1H, m), 4.20-3.80 (2H, m), 4.45 (2H, d, J=5.4Hz), 6.35 (1H, d, J=3.3Hz), 6.55 (1H, s), 6.58 (1H, d, J=3.3Hz), 6.71 (1H, s), 6.78 (4H, s), 8.00 (1H, br), 10.00 (1H, br) Anal. Calcd. for C₁₄H₁₅N₇O₃S : C 46.53, H 4.18, N 27.13 Found C 46.18, H 4.92, N 26.83 Example 47 The following compound was obtained according to a similar manner to that of Example 37. 2-[(Amino){(2,2,2-trifluoroethyl)amino}methyleneamino]-4-(5-methoxycarbonylmethylfuran-2-yl)thiazole. mp : 126 to 127°C IR (Nujol) : 3410, 1715, 1630, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 3.66 (3H, s), 3.84 (2H, s), 4.01-4.22 (2H, m), 6.36 (1H, d, J=3Hz), 6.66 (1H, d, J=3Hz), 6.89 (1H, s), 7.14 (1H, br s), 7.76 (2H, s) Example 48 The following compounds were obtained according to a similar manner to that of Example 38. 2-[(Amino){(2,2,2-trifluoroethyl)amino}methyleneamino]-4-(5-carbamoylmethylfuran-2-yl)thiazole. mp : 163 to 165°C IR (Nujol) : 3350, 3190, 1660, 1620, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 3.50 (2H, s), 3.90-4.27 (2H, m), 6.27 (1H, d, J=3Hz), 6.63 (1H, d, J=3Hz), 6.86 (1H, s), 6.94-7.30 (2H, m), 7.47 (1H, s), 7.75 (2H, br s) Anal. Calcd. for C₁₂H₁₂N₅O₂SF₃ : C 41.50, H 3.48, N 20.16 Found C 41.10, H 3.45, N 19.51 2-(Diaminoethyleneamino)-4-(5-methylcarbamoylmethylfuran-2-yl)thiazole. mp : 212 to 213°C IR (Nujol) : 3420, 3350, 1660, 1610, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 2.61 (3H, d, J=5Hz), 3.51 (2H, s), 6.22 (1H, d, J=3Hz), 6.56 (1H, d, J=3Hz), 6.71 (1H, s), 6.84 (4H, s), 7.75 (1H, br s) Mass : m/e 279 (M⁺) Anal. Calcd. for C₁₁H₁₃N₅O₂S : C 47.30, H 4.69, N 25.07 Found C 47.54, H 4.37, N 25.43 Example 49 The following compound was obtained according to a similar manner to that of Example 39. 4-[5-(2-Amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole methanesulfonate. mp : 221 to 223°C (dec.) IR (Nujol) : 3400, 3300, 3180, 3110, 1690, 1630, 1575 cm⁻¹ NMR (DMSO-d₆, δ) : 2.53 (3H, s), 3.65 (2H, s), 6.40 (1H, d, J=3Hz), 6.56 (1H, br s), 6.95 (1H, d, J=3Hz), 7.31 (1H, s), 7.41 (1H, br s), 8.31 (4H, s) Anal. Calcd. for C₁₀H₁₃N₇O₃S₂·CH₃SO₃H : C 30.06, H 3.90, N 22.31, S 21.89 Found C 30.03, H 3.91, N 22.54, S 21.87 Example 50 The following compound was obtained according to a similar manner to that of Example 29. 2-(Diaminomethyleneamino)-4-(5-methylsulfamoylaminomethylfuran-2-yl)thiazole. mp : 197°C IR (Nujol) : 3420, 3275, 1600 cm⁻¹ NMR (DMSO-d₆, δ) : 2.41 (3H, d, J=5.5Hz), 3.98 (2H, d, J=6.0Hz), 6.32 (1H, d, J=3.0Hz), 6.55 (1H, d, J=3.0Hz), 6.62-6.72 (1H, m), 6.73 (1H, s), 6.82 (4H, s), 7.30 (1H, t, J=6.0Hz) Anal. Calcd. for C₁₀H₁₄N₆O₃S₂ : C 36.35, H 4.27, N 25.44 Found C 36.38, H 4.26, N 25.24 Example 51 The following compound was obtained according to a similar manner to that of Example 41. 2-(Diaminomethyleneamino)-4-(5-hydrazinocarbonylmethylfuran-2-yl)thiazole. mp : 222 to 223°C IR (Nujol) : 3450, 3350, 3200, 1645, 1605, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 3.53 (2H, s), 4.35 (2H, br s), 6.31 (1H, d, J=3Hz), 6.64 (1H, d, J=3Hz), 6.77 (1H, s), 6.94 (4H, s), 9.25 (1H, s) Example 52 The following compound was obtained according to a similar manner to that of Example 42. 2-(Diaminomethyleneamino)-4-(5-guanidinocarbamoylmethylfuran-2-yl)thiazole. mp : 250 to 251°C IR (Nujol) : 3300, 3160, 1650, 1600, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 3.43 (2H, s), 6.22 (1H, d, J=3Hz), 6.60 (1H, d, J=3Hz), 6.73 (1H, s), 6.93 (4H, s) Example 53 The following compound was obtained according to a similar manner to that of Example 43. 4-[5-(3-Amino-1H-1,2,4-triazol-5-yl)methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 259 to 261°C (dec.) IR (Nujol) : 3410, 3120, 1660, 1640, 1600, 1550 cm⁻¹ NMR (DMSO-d₆, δ) : 3.83 (2H, s), 5.71 (2H, br s), 6.18 (1H, d, J=3Hz), 6.56 (1H, d, J=3Hz), 6.70 (1H, s), 6.86 (4H, s) Anal. Calcd. for C₁₁H₁₂N₈OS·1/2H₂O : C 42.17, H 4.18, N 35.76, H₂O 2.87 Found C 42.12, H 4.12, N 35.96, H₂O 3.00 Example 54 An ice-cooling mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (0.8 g), 3-chlorobenzoisothiazol-1,1-dioxide (0.8 g) and triethylamine (0.5 ml) in N,N-dimethylformamide (15 ml) was stirred for 3 hours. To a reaction mixture was added a mixture of ethyl acetate, tetrahydrofuran and water and the mixture was adjusted to pH 9.5 with 20% aqueous potassium carbonate. The separated organic layer was washed with brine and dried over magnesium sulfate. The solvent was removed by concentration and a residue was recrystallized from a mixture of methanol, dioxane and diisopropyl ether to give 2-(diaminomethyleneamino)-4-[5-(1,1-dioxobenzoisothiazol-3-yl)aminomethylfuran-2-yl]thiazole (0.49 g). mp : 255 to 256°C (dec.) IR (Nujol) : 3430, 3320, 1660, 1620, 1590, 1535 cm⁻¹ NMR (DMSO-d₆, δ) : 4.73 (2H, s), 6.51 (1H, d, J=3Hz), 6.67 (1H, d, J=3Hz), 6.82 (1H, s), 6.88 (4H s), 7.63-8.06 (3H, m), 8.09-8.40 (1H, m), 9.89 (1H, br s) Anal. Calcd. for C₁₆H₁₄N₆O₃S₂·1/3H₂O : C 47.05, H 3.62, N 20.49, H₂O 1.47 Found C 47.04, H 4.28, N 20.49, H₂O 1.71 Example 55 The following compound was obtained according to a similar manner to that of Example 54. 4-[5-(7-Chloro-1,1-dioxo-4H-1,2,4-benzothiadiazin-3-yl)aminomethylfuran-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 220 to 221°C IR (Nujol) : 3325, 1690, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.49 (2H, d, J=4.5Hz), 6.42 (1H, d, J=3Hz), 6.71 (1H, d, J=3Hz), 6.94 (1H, s), 7.24 (4H, br s), 7.26 (1H, d, J=8.5Hz), 7.63 (1H, dd, J=2Hz and 8.5Hz), 7.69 (1H, d, J=2Hz), 7.95 (1H, br s) and 11.07 (1H, br s) Anal. Calcd. for C₁₆H₁₄ClN₇O₃S₂·1.5H₂O : C 40.13, H 3.58, N 20.47 Found C 40.10, H 3.56, N 20.61 Example 56 To a mixture of 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole (15.4 g) in methanol (160 ml) was added a solution of 19% (W/V) hydrogen chloride in methanol (31.6 ml) and the mixture was stirred for an hour at ambient temperature. To a reaction mixture was added a isopropyl ether and the isolated precipitate was collected by filtration. The precipitate was recrystallized from an aqueous ethanol to give 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole hydrochloride (6.82 g). mp : 221°C IR (Nujol) : 3400, 3300, 1695, 1655, 1620, 1590, 1565 cm⁻¹ NMR (DMSO-d₆, δ) : 4.23 (2H, d, J=5Hz), 5.67 (2H, s), 6.32 (1H, d, J=3Hz), 6.55 (1H, t, J=5Hz), 6.97 (1H, d, J=3Hz), 7.31 (1H, s), 8.35 (4H, s) Anal. Calcd. for C₁₀H₁₂N₆O₂S·HCl·H₂O : C 35.88, H 4.22, N 25.10, Cl 10.58, H₂O 5.38 Found C 35.77, H 4.47, N 25.08, Cl 10.79, H₂O 5.63 Example 57 A solution of conc. sulfuric acid (0.7 ml) in methanol (10 ml) was added to a mixture of 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole (4.0 g) in methanol (60 ml) and the mixture was stirred for an hour at ambient temperature. The isolated precipitate was collected by filtration and the precipitate was recrystallized from an aqueous ethanol to give 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole hemisulfate (4.26 g). mp : 170 to 172°C IR (Nujol) : 3400, 3290, 1690, 1650, 1620, 1580, 1565, 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 4.21 (2H, d, J=6Hz), 5.61 (2H, s), 6.29 (1H, d, J=3Hz), 6.45 (1H, t, J=6Hz), 6.80 (1H, d, J=3Hz), 7.09 (1H, s), 7.86 (4H, s) Example 58 Methanesulfonic acid (0.93 ml) was added to a mixture of 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole (4.0 g) in methanol (60 ml) and the mixture was stirred for an hour at ambient temperature. The isolated precipitate was collected by filtration and the precipitate was recrystallized from a solution of an aqueous ethanol to give 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole methanesulfonate (2.77 g) . mp : 185 to 186°C IR (Nujol) : 3325, 3125, 1690, 1640 (br), 1545, 1510, 1045 cm⁻¹ NMR (DMSO-d₆, δ) : 2.48 (3H, s), 4.22 (2H, d, J=5Hz), 5.62 (2H, s), 6.32 (1H, d, J=3Hz), 6.48 (1H, t, J=5Hz), 6.95 (1H, d, J=3Hz), 7.32 (1H, s), 8.34 (4H, s), 12.12 (1H, s) Anal. Calcd. for C₁₀H₁₂N₆O₂S·CH₃SO₃H : C 35.10, H 4.28, N 22.33 Found C 34.96, H 4.22, N 22.35 Example 59 A mixture of acetic anhydride (2.4 ml) and formic acid (1.0 ml) was stirred for 30 minutes at 50 to 60°C. The above mixture was added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (1.5 g) in tetrahydrofuran (15 ml) and N,N-dimethylformamide (15 ml) at ambient temperature and the mixture was stirred for 2.5 hours at ambient temperature. To the reaction mixture was added a mixture of ethyl acetate, tetrahydrofuran and water and the mixture was adjusted to pH 9.5 with 20% aqueous potassium carbonate. The separated organic layer was washed with a brine and dried over magnesium sulfate. The solvent was removed by concentration in vacuo and the residue was recrystallized from a mixture of methanol, dioxane and tetrahydrofuran to give 2-(diaminomethyleneamino)-4-(5-formamidomethylfuran-2-yl)thiazole (0.80 g). mp : 179 to 181°C IR (Nujol) : 3350, 3310, 3130, 1650, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 4.36 (2H, d, J=6Hz), 6.37 (1H, d, J=3Hz), 6.78 (1H, d, J=3Hz), 7.11 (1H, s), 8.11 (1H, s), 8.56 (4H, s) Example 60 The mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (4.0 g), furfurylthioacetic acid (3.4 g) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (4.2 g) in N,N-dimethylformamide (40 ml) was stirred for 15 hours at ambient temperature. The mixture was added a mixture of ethyl acetate, tetrahydrofuran and water and the mixture was adjusted to pH 9.5 with potassium carbonate. The separated organic layer was washed with a brine and dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of ethyl acetate and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a mixture of methanol, dioxane and isopropyl ether to give 2-(diaminomethyleneamino)-4-[5-{(furan-2-yl)methylthio}acetamidomethylfuran-2-yl]thiazole (3.50 g). mp : 180 to 181°C IR (Nujol) : 3400, 3190, 1655, 1630, 1610, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 3.14 (2H, s), 3.85 (2H, s), 4.30 (2H, d, J=5Hz), 6.19-6.44 (3H, m), 6.59 (1H, d, J=3Hz), 6.74 (1H, s), 6.87 (4H, s), 7.55 (1H, s), 8.48 (1H, t, J=5Hz) Anal. Calcd. for C₁₆H₁₇N₅O₃S₂ : C 49.09, H 4.38, N 17.89 Found C 49.25, H 4.40, N 17.98 Example 61 A mixture of 2-(diaminomethyleneamino)-4-[5-{(furan-2-yl)methylthio}acetamidomethylfuran-2-yl]thiazole (1.5 g) and 3-chloroperbenzoic acid (0.9 g) in a mixture of tetrahydrofuran (30 ml) and N,N-dimethylformamide (10 ml) was stirred for 1.5 hours at ambient temperature. To the reaction mixture was added a solution of water and ethyl acetate and the mixture was adjusted to pH 9.5 with 20% aqueous potassium carbonate. The separated organic layer was washed with brine and dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of ethyl acetate and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a mixture of methanol, dioxane and isopropyl ether to give 2-(diaminomethyleneamino)-4-[5-{(furan-2-yl)methylsulfinyl}acetamidomethylfuran-2-yl]thiazole (1.5 g). mp : 208 to 209°C IR (Nujol) : 3425, 3260, 3070, 1650, 1595, 1540 cm⁻¹ NMR (DMSO-d₆, δ) : 3.16 (1H, d, J=13Hz), 3.79 (1H, d, J=13Hz), 4.16 (1H, d, J=14Hz), 4.34 (2H, d, J=5Hz), 4.36 (1H, d, J=14Hz), 6.35 (1H, d, J=3Hz), 6.44-6.48 (2H, m), 6.61 (1H, d, J=3Hz), 6.78 (1H, s), 6.89 (4H, s), 7.69 (1H, s), 8.83 (1H, t, J=5Hz) Anal. Calcd. for C₁₆H₁₇N₅O₄S₂ : C 47.16, H 4.21, N 17.19 Found C 47.15, H 4.15, N 17.02 Example 62 A suspension of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (8.0 g) and S-methylisothiourea hemisulfate (11.08 g in dimethyl sulfoxide (250 ml) was heated at 100°C for 6 hours. The resulting precipitate was collected by filtration and then suspended in water (50 ml). The suspension was alkalized to pH 13 with a 4N-sodium hydroxide solution. The resulting precipitate was collected by filtration to afford 2-(diaminomethyleneamino)-4-(5-guanidinomethylfuran-2-yl)thiazole (8.26 g). NMR (DMSO-d₆, δ) : 4.30 (2H, s), 6.35 (1H, d, J=3.0Hz), 6.58 (1H, d, J=3.0Hz), 6.77 (4H,s), 7.6-6.7 (4H, br) Example 63 A solution of hydrogen chloride in methanol (0.19 g/ml, 3 ml) was added slowly to a suspension of 2-(diaminomethyleneamino)-4-(5-guanidinomethylfuran-2-yl)thiazole (500 mg) in methanol (10 ml) with cooling on an ice-water bath. The mixture was stirred with cooling on an ice-water bath for 2 hours. The mixture was diluted with diisopropyl ether (20 ml) and the resulting precipitate was collected by filtration. Recrystallization from a mixture of methanol, tetrahydrofuran and diisopropyl ether afforded 2-(diaminomethyleneamino)-4-(5-guanidinomethylfuran-2-yl)thiazole dihydrochloride (340 mg). mp : 255°C IR (Nujol) : 3230, 1680, 1620 cm⁻¹ NMR (DMSO-d₆, δ) : 4.48 (2H, d, J=6.0Hz), 6.52 (1H, d, J=3.5Hz), 7.02 (1H, d, J=3.5Hz), 7.35 (1H, s), 7.45 (4H, s), 8.24 (1H, t, J=6.0Hz), 8.36 (4H, s), 12.80 (1H, s) Anal. Calcd. for C₁₀H₁₃N₇OS·2HCl : C 34.10, H 4.29, N 27.84, Cl 20.13 Found C 34.08, H 4.29, N 27.41, Cl 19.85 Example 64 A suspension of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (1.6 g), imino(methylthio)methylcarbamic acid methylester (1.2 g) and triethylamine (1.5 g) was stirred at room temperature for 26 hours and then refluxed for 2.5 hours. Imino(methylthio)methylcarbamic acid methylester (1.0 g) was added to the reaction mixture and the mixture was refluxed for 10 hours. The solvent was removed under reduced pressure. The residue was chromatographed on a silica gel column eluting with a mixture of chloroform and methanol (10:1, V/V). Recrystallization from a mixture of methanol and diisopropyl ether afforded 2-(diaminomethyleneamino)-4-[5-(2-methoxycarbonylguanidino)methylfuran-2-yl]thiazole (530 mg). mp : 199 to 200°C (dec.) IR (Nujol) : 3450, 3375, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 3.48 (3H, s), 4.39 (2H, s), 6.33 (1H, d, J=3.0Hz), 6.62 (1H, d, J=3.0Hz), 6.79 (1H, s), 6.90 (4H, s), 7.37 (1H, br) Anal. Calcd. for C₁₂H₁₅N₇O₃S : C 42.72, H 4.48, N 29.06 Found C 42.92, H 4.62, N 28.82 Example 65 A suspension of 2-(diaminomethyleneamino)-4-(5-thioureidomethylfuran-2-yl)thiazole (1.0 g) and methyl iodide (600 mg) in methanol was stirred at room temperature for 34 hours. The solvent was removed under reduced pressure to afford 2-(diaminomethyleneamino)-4-[5-(2-methyl-3-isothioureido)methylfuran-2-yl]thiazole hydriodide (1.3 g). NMR (DMSO-d₆, δ) : 2.63 (3H, s), 4.61 (2H, s), 6.53 (1H, d, J=3.0Hz), 6.69 (1H, d, J=3.0Hz), 6.83 (1H, s), 6.80-7.40 (7H, br), 9.42 (1H, br) Example 66 A solution of 2-(diaminomethyleneamino)-4-[5-(2-methyl-3-isothioureido)methylfuran-2-yl]thiazole hydriodide (1.0 g), cyanamide (120 g) and triethylamine (1.2 g) in N,N-dimethylformamide (20 ml) was heated at 100°C for 3 hours. The solvent was removed under reduced pressure. The residue was chromatographed on a silica gel column eluting with a mixture of chloroform and methanol (20:1, V/V). Recrystallization from 20% methanol afforded 2-(diaminomethyleneamino)-4-[5-(2-cyanoguanidino)methylfuran-2-yl]thiazole (170 mg). mp : 224 to 225°C IR (Nujol) : 3310, 3200, 2180, 1630 cm⁻¹ NMR (DMSO-d₆, δ) : 4.30 (2H, d, J=5.5Hz), 6.33 (1H, d, J=3.0Hz), 6.62 (1H, d, J=3.0Hz), 6.78 (1H, s), 6.80 (2H, br), 6.88 (4H, s), 7.25 (1H, br) Anal. Calcd. for C₁₁H₁₂N₈OS·7/10 H₂O : C 41.69, H 4.26, N 35.35, H₂O 3.98 Found C 41.61, H 4.33, N 35.00, H₂O 3.70 Example 67 A mixture of 3-acetoxypropionic acid (2.5 g), diphenylphosphorylazide (4.3 ml) and triethylamine (2.6 ml) in dry benzene (50 ml) was stirred for an hour at 75 to 80°C. To the mixture was added to a mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (3.0 g) in a solution of tetrahydrofuran (45 ml) and methanol (45 ml) at ambient temperature, and the mixture was stirred for 2.5 hours at the same temperature. Evaporation of a solvent gave a residue, which was purified by column chromatography on silica gel eluting with a mixture of ethyl acetate and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a mixture of methanol, dioxane and isopropyl ether to give 4-[5-{3-(2-acetoxyethyl)ureido}methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole (1.82 g). mp : 200 to 202°C IR (Nujol) : 3380, 1725, 1655, 1600, 1550 (br) cm⁻¹ NMR (DMSO-d₆, δ) : 2.00 (3H, s), 3.07-3.43 (2H, m), 3.97 (2H, t, J=5Hz), 4.20 (2H, d, J=5Hz), 6.04 (1H, t, J=5Hz), 6.19 (1H, d, J=3Hz), 6.33 (1H, t, J=5Hz), 6.53 (1H, d, J=3Hz), 6.70 (1H, s), 6.82 (4H, s) Anal. Calcd. for C₁₄H₁₈N₆O₄S : C 45.89, H 4.95, N 22.94 Found C 45.67, H 4.87, N 22.72 Example 68 A mixture of 4-[5-{3-(2-acetoxyethyl)ureido}methylfuran-2-yl]-2-(diaminomethyleneamino)thiazole (1.0 g) in methanol (30 ml) and 1N-sodium hydroxide (8.2 ml) was stirred for 2 hours at ambient temperature. The solvent was removed by concentration in vacuo and to the residue was added a mixture of ethyl acetate, tetrahydrofuran and water. The separated organic layer was washed with brine and dried over magnesium sulfate. Evaporation of a solvent gave a residue, which was purified by column chromatography on alumina eluting with a mixture of chloroform and methanol (9:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was recrystallized from a mixture of methanol, dioxane and isopropyl ether to give 2-(diaminomethyleneamino)-4-[5-{3-(2-hydroxyethyl)ureido}methylfuran-2-yl]thiazole (0.42 g). mp : 201 to 203°C IR (Nujol) : 3380, 3340, 1635, 1605, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 3.00-3.15 (2H, m), 3.28-3.48 (2H, m), 4.22 (2H, d, J=6Hz), 4.68 (1H, t, J=5Hz), 6.00 (1H, t, J=6Hz), 6.24 (1H, d, J=3Hz), 6.41 (1H, t, J=6Hz), 6.59 (1H, d, J=3Hz), 6.76 (1H, s), 6.90 (4H, s) Anal. Calcd. for C₁₂H₁₆N₆O₃S·1/5H₂O : C 43.95, H 5.04, N 25.63 Found C 43.96, H 4.84, N 25.51 Example 69 A solution of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (1.50 g) and diphenyl cyanocarbonimidate (1.51 g) in methanol (20 ml) was stirred for 4 hours at room temperature. After the solvent was evaporated in vacuo, acetonitrile (20 ml) and methylhydrazine (1.46 g) was added to the residue and the mixture was stirred for three hours at room temperature. The solvent was evaporated in vacuo and the residue was mixed with water. The mixture was made acidic with 6N-hydrochloric acid and washed with diethyl ether. The acidic solution was made basic to pH 11 with aqueous potassium carbonate and the resulting precipitate was collected by filtration. The product was converted to the hydrochloric acid in an usual manner, and which was recrystallized from a mixture of methanol, water and diisopropyl ether to give 4-[5-(3-amino-1-methyl-1H-1,2,4-triazol-5-yl)aminomethylfuran-2-yl]-2-(diaminomethyleneamino)thiazole dihydrochloride (0.61 g). mp : 184 to 185°C IR (Nujol) : 3300, 3175, 1675, 1650 cm⁻¹ NMR (DMSO-d₆, δ) : 3.48 (3H, s), 4.58 (2H, d, J=5Hz), 6.61 (1H, d, J=3Hz), 7.04 (1H, d, J=3Hz), 7.36 (1H, s), 8.43 (4H, s) and 8.91 (1H, t, J=5Hz) Anal. Calcd for C₁₂H₁₅N₉OS·2HCl·H₂O : C 33.97, H 4.51, N 29.71, Cl 16.71, H₂O 4.25 Found C 34.17, H 4.54, N 29.17, Cl 16.30, H₂O 3.77 Example 70 A mixture of 4-[5-(2-amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole (2.0 g) in N,N-dimethylformamide (15 ml) and 1N-hydrochloric acid (17.5 ml) was stirred for 87 hours at ambient temperature. To a water (50 ml) was added a reaction mixture and the mixture was adjusted to pH 9.5 with 20% aqueous potassium carbonate. The isolated precipitate was collected by filtration and the precipitate was recrystallized from aqueous N,N-dimethylformamide to give 2-(diaminomethyleneamino)-4-(5-sulfamoylaminocarbonylmethylfuran-2-yl)thiazole (1.1 g). mp : 179 to 181°C IR (Nujol) : 3350, 3280, 3210, 3100, 1690, 1620, 1580, 1570, 1510 cm⁻¹ NMR (DMSO-d₆, δ) : 3.68 (2H, s), 6.33 (1H, d, J=3Hz), 6.63 (1H, d, J=3Hz), 6.77 (1H, s), 6.92 (4H, s), 7.42 (2H, s) Example 71 A mixture of 4-(5-aminomethylfuran-2-yl)-2-(diaminomethyleneamino)thiazole (8.00 g) and dimethyl N-cyanodithioiminocarbonate (1.54 g) in ethanol (80 ml) was refluxed for two hours with stirring. After cooling to room temperature, diisopropyl ether (80 ml) was added and the resulting precipitate was collected filtration. Recrystallization from a mixture of N,N-dimethylformamide and ethyl acetate to give 2-(diaminomethyleneamino)-4-[5-(3-cyano-2-methyl-1-isothioureido)methylfuran-2-yl]thiazole (10.2 g). IR (Nujol) : 3450, 3300, 3270, 2165, 1655 cm⁻¹ Example 72 The following compound was obtained according to a similar manner to that of Example 1. 2-(Diaminomethyleneamino)-4-[5-(2-methylimidazol-4-yl)furan-2-yl]thiazole dihydrochloride. mp : >300°C IR (KBr) : 3000, 1680, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 2.64 (3H, s), 7.14 (1H, d, J=3.5Hz), 7.23 (1H, d, J=3.5Hz), 7.60 (1H, s), 7.90 (1H, s) and 8.38 (4H, s) Example 73 The following compounds were obtained according to a similar manner to that of Example 1. 4-[5-(2-Amino-2-aminosulfonyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole. mp : 222-225°C (dec.) IR (Nujol) : 3470, 3450, 3400, 3350, 3320, 3230, 1620, 1530 cm⁻¹ NMR (DMSO-d₆, δ) : 3.58 (2H, s), 6.28 (1H, d, J=3Hz), 6.52 (2H, s), 6.56 (1H, d, J=3Hz), 6.73 (1H, s), 6.81 (4H, s), 7.35 (1H, s), 8.18 (1H, s) 2-(Diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole. mp : 214-215°C IR (Nujol) : 3400, 3320, 3130, 1650, 1590 cm⁻¹ NMR (DMSO-d₆, δ) : 4.19 (2H, d, J=5Hz), 5.53 (2H, s), 6.24 (1H, d, J=3Hz), 6.36 (1H, t, J=5Hz), 6.59 (1H, d, J=3Hz), 6.76 (1H, s), 6.87 (4H, s) Anal. Calcd. for C₁₀H₁₂N₆O₂S·1/3 H₂O C 41.95, H 4.46, N 29.35, H₂O 2.10 Found C 42.04, H 4.53, N 29.04, H₂O 2.33

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR, GB, IT, LI, LU, NL, SE A compound of the formula : wherein R¹ and R² are each hydrogen, furoyl or C₁-C₆ alkyl which may have halogen; or R¹ and R² are linked together to form C₁-C₆ alkylene, R³ is hydrogen or C₁-C₆ alkyl, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted by nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or dl(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n is 0 or 1, X is =CH- or =N-, R⁵ is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, R⁶ is hydrogen, C₁-C₆ alkyl, C₁-C₆ alkylthio, C₁-C₆ alkoxy, amino, mono or di(C₁-C₆)alkylamino, allylamino, propargylamino, hydroxy(C₁-C₆)alkylamino, C₁-C₆ alkoxy(C₁-C₆)alkylamino, or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino; A is C₁-C₆ alkylene or -CONH- ; or A-R⁴ is imidazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, and Q is hydrogen, or C₁-C₆ alkyl, and pharmaceutically acceptable salts thereof. A compound of claim 1, wherein R¹ and R² are each hydrogen, C₁-C₆ alkyl or trihalo(C₁-C₆)alkyl; or R¹ and R² are linked together to form C₁-C₆ alkylene, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, nitrobenzoylamino, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, 3-C₁-C₆ alkylureido, 3-C₁-C₆ alkylthioureido, 3-C₁-C₆ alkanoylureido, 3-allylureido, 3-benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, 3-hydroxy(C₁-C₆)alkylureido, 3-C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, 2-C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n, X and R⁶ are as defined in claim 1, R⁵ is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, phenylsulfonyl substituted with C₁-C₆ alkyl, phenylsulfonyl substituted with C₁-C₆ alkoxy, phenylsulfonyl substituted with halogen, phenylsulfonyl substituted with amino, mono or di(C₁-C₆)alkylsulfamoyl, A is as defined in claim 1 ; or A-R⁴ is as defined in claim 1, and R³ and Q are each as defined in claim 1. A compound of claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is a group of the formula : wherein R⁵ is sulfamoyl, and R⁶ is amino, A is C₁-C₆ alkylene, and Q is hydrogen. A compound of claim 3, which is 4-[5-(2-amino-2-sulfamoyliminoethyl)furan-2-yl]-2-(diaminomethyleneamino)thiazole or its hydrochloride or its methanesulfonate. A compound of claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is ureido or 3-C₁-C₆ alkylureido, A is C₁-C₆ alkylene, and Q is hydrogen. A compound of claim 5, which is selected from the group consisting of 2-(diaminomethyleneamino)-4-(5-ureidomethylfuran-2-yl)thiazole or its hydrochloride, and 2-(diaminomethyleneamino)-4-[5-(3-methylureido)methylfuran-2-yl]thiazole or its hydrochloride. A process for preparing a compound of the formula : wherein R¹, R², R³, R⁴, R⁵, R⁶, A, A-R⁴, Q, X and n are each as defined in claim 1, or a salt thereof, which comprises, (1) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, and Z¹ is halogen, or a salt thereof, with a compound of the formula : wherein R¹ and R² are each as defined above, to give a compound of the formula : wherein R¹, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (2) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / a is ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted with nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, or C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to deacylation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (3) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to acylation reaction, to give a compound of the formula : wherein R¹, R², R³, R 4 / a, A and Q are each as defined above, or a salt thereof, or (4) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : (R⁷-X¹)₂C=X-R⁵ wherein R⁵ and X are each as defined above, R⁷ is C₁-C₆ alkyl or phenyl, and X¹ is S or O, to give a compound of the formula : wherein R¹, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, or (5) reacting a compound of the formula : wherein R¹, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H-R 6 / a wherein R 6 / a is amino which may have mono or di(C₁-C₆)alkyl, allyl, propargyl, hydroxy(C₁-C₆)alkyl or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkyl, or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R 6 / a, X, A and Q are each as defined above, or a salt thereof, or (6) subjecting a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, or (7) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R⁸ is amino-protective group consisting of C₁-C₆ alkanoyl and benzoyl, or a salt thereof, to elimination reaction of the amino-protective group, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (8) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : Z²-CH₂-CO-R⁹ wherein R⁹ is C₁-C₆ alkyl, and Z² is halogen, to give a compound of the formula : wherein R¹, R², R³, R⁹, A and Q are each as defined above, or a salt thereof, or (9) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R⁵, R⁶ and X are each as defined above, and R¹⁰ is C₁-C₆ alkanoyloxy, phenyl(C₁-C₆)alkoxy, C₁-C₆ alkoxy(C₁-C₆)alkoxy, tetrahydropyranyloxy or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R⁶, X, A and Q are each as defined above, or a salt thereof, or (10) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹¹OH wherein R¹¹ is C₁-C₆ alkyl, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (11) reacting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R¹² wherein R¹² is acyl, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, or (12) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹³-Z³ wherein R¹³ is C₁-C₆ alkyl, and Z³ is halogen, or a salt thereof, to give a compound of the formula: wherein R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, and continuously reacting it with a compound of the formula : H₂N-Y-NH₂ wherein Y is C₁-C₆ alkylene, or a salt thereof, to give a compound of the formula : wherein R³, R⁴, A, Q and Y are each as defined above, or a salt thereof, or (13) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to reduction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (14) reacting a compound of the formula : wherein R², R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R 1 / a wherein R 1 / a is C₁-C₆ alkyl which may have halogen, or a salt thereof, to give a compound of the formula: wherein R 1 / a, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (15) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (16) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to amidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (17) reacting a compound of the formula : wherein R¹, R², R³, R⁷, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁴NHNH₂ wherein R¹⁴ is hydrogen or C₁-C₆ alkyl, to give a compound of the formula : wherein R¹, R², R³, R¹⁴, A and Q are each as defined above, or a salt thereof, or (18) reacting a compound of the formula : wherein R¹, R², R³ and Q are each as defined above, R¹⁵ is C₁-C₆ alkyl, and A¹ is C₁-C₆ alkylene or bond, or a salt thereof, with hydrazine, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (19) reacting a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, with S-C₁-C₆ alkylisothiourea or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (20) subjecting a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, to ring closure, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (21) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁶-Z⁴ wherein R¹⁶ is thiazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, triazolyl substituted with amino and C₁-C₆ alkyl, benzoisothiazolyl substituted with oxo, or benzothiadiazinyl substituted with oxo, and Z⁴ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁶, A and Q are each as defined above, or a salt thereof, or (22) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / b is furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, or a salt thereof, to oxidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / c is furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, or a salt thereof, or (23) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁷-Z⁵ wherein R¹⁷ is C₁-C₆ alkyl, and Z⁵ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, or (24) reacting a compound of the formula : wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H₂N-R⁵ wherein R⁵ is as defined above, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R⁵, A and Q are each as defined above, or a salt thereof, or (25) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / d is C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to elimination reaction of C₁-C₆ alkanoyl, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / e is hydroxy(C₁-C₆)alkylureido, or a salt thereof, or (26) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R¹⁸ is C₁-C₆ alkyl, and R¹⁹ is carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁹, A and Q are each as defined above, or a salt thereof, or (27) subjecting a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof. A pharmaceutical composition which comprises, as an active ingredient, a compound of claim 1 or a pharmaceutically acceptable salt thereof in admixture with pharmaceutically acceptable carriers. Use of a compound of claim 1 or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the therapeutic treatment of ulcer in human beings or animals. A compound of claim 1 or a pharmaceutically acceptable salt thereof for use as a medicament. Claims for the following Contracting State : ES A process for preparing a compound of the formula : wherein R¹ and R² are each hydrogen, furoyl or C₁-C₆ alkyl which may have halogen; or R¹ and R² are linked together to form C₁-C₆ alkylene, R³ is hydrogen or C₁-C₆ alkyl, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted by nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n is 0 or 1, X is =CH- or =N-, R⁵ is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, R⁶ is hydrogen, C₁-C₆ alkyl, C₁-C₆ alkylthio, C₁-C₆ alkoxy, amino, mono or di(C₁-C₆)alkylamino, allylamino, propargylamino, hydroxy(C₁-C₆)alkylamino, C₁-C₆ alkoxy(C₁-C₆)alkylamino, or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino; A is C₁-C₆ alkylene or -CONH- ; or A-R⁴ is imidazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, and Q is hydrogen, or C₁-C₆ alkyl, or a salt thereof, which comprises (1) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, and Z¹ is halogen, or a salt thereof, with a compound of the formula : wherein R¹ and R² are each as defined above, to give a compound of the formula : wherein R¹, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (2) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / a is ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted with nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, or C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to deacylation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (3) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to acylation reaction, to give a compound of the formula : wherein R¹, R², R³, R 4 / a, A and Q are each as defined above, or a salt thereof, or (4) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : (R⁷-X¹)₂C=X-R⁵ wherein R⁵ and X are each as defined above, R⁷ is C₁-C₆ alkyl or phenyl, and X¹ is S or O, to give a compound of the formula : wherein R1, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, or (5) reacting a compound of the formula : wherein R¹, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H-R 6 / a wherein R 6 / a is amino which may have mono or di(C₁-C₆)alkyl, allyl, propargyl, hydroxy(C₁-C₆)alkyl or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkyl, or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R 6 / a, X, A and Q are each as defined above, or a salt thereof, or (6) subjecting a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, or (7) subjecting a compound of the formula : wherein R1, R², R³, A and Q are each as defined above, and R⁸ is amino-protective group consisting of C₁-C₆ alkanoyl and benzoyl, or a salt thereof, to elimination reaction of the amino-protective group, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (8) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : Z²-CH₂-CO-R⁹ wherein R⁹ is C₁-C₆ alkyl, and Z² is halogen, to give a compound of the formula : wherein R¹, R², R³, R⁹, A and Q are each as defined above, or a salt thereof, or (9) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R⁵, R⁶ and X are each as defined above, and R¹⁰ is C₁-C₆ alkanoyloxy, phenyl(C₁-C₆)alkoxy, C₁-C₆ alkoxy(C₁-C₆)alkoxy, tetrahydropyranyloxy or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R⁶, X, A and Q are each as defined above, or a salt thereof, or (10) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹¹OH wherein R¹¹ is C₁-C₆ alkyl, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (11) reacting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R¹² wherein R¹² is acyl, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, or (12) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹³-Z³ wherein R¹³ is C₁-C₆ alkyl, and Z³ is halogen, or a salt thereof, to give a compound of the formula: wherein R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, and continuously reacting it with a compound of the formula : H₂N-Y-NH₂ wherein Y is C₁-C₆ alkylene, or a salt thereof, to give a compound of the formula : wherein R³, R⁴, A, Q and Y are each as defined above, or a salt thereof, or (13) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to reduction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (14) reacting a compound of the formula : wherein R², R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R 1 / a wherein R 1 / a is C₁-C₆ alkyl which may have halogen, or a salt thereof, to give a compound of the formula: wherein R 1 / a, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (15) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (16) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to amidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (17) reacting a compound of the formula : wherein R¹, R², R³, R⁷, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁴NHNH₂ wherein R¹⁴ is hydrogen or C₁-C₆ alkyl, to give a compound of the formula : wherein R1, R², R³, R¹⁴, A and Q are each as defined above, or a salt thereof, or (18) reacting a compound of the formula : wherein R¹, R², R³ and Q are each as defined above, R¹⁵ is C₁-C₆ alkyl, and A¹ is C₁-C₆ alkylene or bond, or a salt thereof, with hydrazine, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (19) reacting a compound of the formula : wherein R1, R², R³, A¹ and Q are each as defined above, or a salt thereof, with S-C₁-C₆ alkylisothiourea or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (20) subjecting a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, to ring closure, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (21) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁶-Z⁴ wherein R¹⁶ is thiazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, triazolyl substituted with amino and C₁-C₆ alkyl, benzoisothiazolyl substituted with oxo, or benzothiadiazinyl substituted with oxo, and Z⁴ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁶, A and Q are each as defined above, or a salt thereof, or (22) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / b is furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, or a salt thereof, to oxidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / c is furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, or a salt thereof, or (23) reacting a compound of the formula : wherein R1, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁷-Z⁵ wherein R¹⁷ is C₁-C₆ alkyl, and Z⁵ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, or (24) reacting a compound of the formula : wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H₂N-R5 wherein R⁵ is as defined above, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R⁵, A and Q are each as defined above, or a salt thereof, or (25) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / d is C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to elimination reaction of C₁-C₆ alkanoyl, to give a compound of the formula : wherein R1, R², R³, A and Q are each as defined above; and R 4 / e is hydroxy(C₁-C₆)alkylureido, or a salt thereof, or (26) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R¹⁸ is C₁-C₆ alkyl, and R¹⁹ is carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁹, A and Q are each as defined above, or a salt thereof, or (27) subjecting a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof. A process according to claim 1, wherein R¹ and R² are each hydrogen, C₁-C₆ alkyl or trihalo(C₁-C₆)alkyl; or R¹ and R² are linked together to form C₁-C₆ alkylene, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, nitrobenzoylamino, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, 3-C₁-C₆ alkylureido, 3-C₁-C₆ alkylthioureido, 3-C₁-C₆ alkanoylureido, 3-allylureido, 3-benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, 3-hydroxy(C₁-C₆)alkylureido, 3-C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, 2-C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n, X and R⁶ are as defined in claim 1, R5 is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, phenylsulfonyl substituted with C₁-C₆ alkyl, phenylsulfonyl substituted with C₁-C₆ alkoxy, phenylsulfonyl substituted with halogen, phenylsulfonyl substituted with amino, mono or di(C₁-C₆)alkylsulfamoyl, A is as defined in claim 1 ; or A-R⁴ is as defined in claim 1, and R³ and Q are each as defined in claim 1. A process according to claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is a group of the formula : wherein R⁵ is sulfamoyl, and R⁶ is amino, A is C₁-C₆ alkylene, and Q is hydrogen. A process according to claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is ureido or 3-C₁-C₆ alkylureido, A is C₁-C₆ alkylene, and Q is hydrogen. A process for the manufacture of a pharmaceutical composition which comprises, as an active ingredient, a compound of claim 1 or a pharmaceutically acceptable salt thereof characterized by mixing a compound of claim 1 with at least one pharmaceutically acceptable carrier or excipient. A process for the manufacture of a composition according to claim 5 for the therapeutic treatment of ulcer in human beings or animals. Claims for the following Contracting State : GR A process for preparing a compound of the formula : wherein R¹ and R² are each hydrogen, furoyl or C₁-C₆ alkyl which may have halogen; or R¹ and R² are linked together to form C₁-C₆ alkylene, R³ is hydrogen or C₁-C₆ alkyl, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted by nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n is 0 or 1, X is =CH- or =N-, R⁵ is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, R⁶ is hydrogen, C₁-C₆ alkyl, C₁-C₆ alkylthio, C₁-C₆ alkoxy, amino, mono or di(C₁-C₆)alkylamino, allylamino, propargylamino, hydroxy(C₁-C₆)alkylamino, C₁-C₆ alkoxy(C₁-C₆)alkylamino, or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkylamino; A is C₁-C₆ alkylene or -CONH- ; or A-R⁴ is imidazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, and Q is hydrogen, or C₁-C₆ alkyl, or a salt thereof, which comprises (1) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, and Z¹ is halogen, or a salt thereof, with a compound of the formula : wherein R¹ and R² are each as defined above, to give a compound of the formula : wherein R¹, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (2) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / a is ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, benzoylamino optionally substituted with nitro, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, C₁-C₆ alkylureido, C₁-C₆ alkylthioureido, C₁-C₆ alkanoylureido, allylureido, benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, hydroxy(C₁-C₆)alkylureido, or C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to deacylation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (3) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to acylation reaction, to give a compound of the formula : wherein R¹, R², R³, R 4 / a, A and Q are each as defined above, or a salt thereof, or (4) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : (R⁷-X¹)₂C=X-R⁵ wherein R⁵ and X are each as defined above, R⁷ is C₁-C₆ alkyl or phenyl, and X¹ is S or O, to give a compound of the formula : wherein R1, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, or (5) reacting a compound of the formula : wherein R¹, R², R³, R⁵, R⁷, X, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H-R 6 / a wherein R 6 / a is amino which may have mono or di(C₁-C₆)alkyl, allyl, propargyl, hydroxy(C₁-C₆)alkyl or mono or di(C₁-C₆)alkylamino(C₁-C₆)alkyl, or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R 6 / a, X, A and Q are each as defined above, or a salt thereof, or (6) subjecting a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R⁶, X, A and Q are each as defined above, or a salt thereof, or (7) subjecting a compound of the formula : wherein R1, R², R³, A and Q are each as defined above, and R⁸ is amino-protective group consisting of C₁-C₆ alkanoyl and benzoyl, or a salt thereof, to elimination reaction of the amino-protective group, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (8) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : Z²-CH₂-CO-R⁹ wherein R⁹ is C₁-C₆ alkyl, and Z² is halogen, to give a compound of the formula : wherein R¹, R², R³, R⁹, A and Q are each as defined above, or a salt thereof, or (9) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R⁵, R⁶ and X are each as defined above, and R¹⁰ is C₁-C₆ alkanoyloxy, phenyl(C₁-C₆)alkoxy, C₁-C₆ alkoxy(C₁-C₆)alkoxy, tetrahydropyranyloxy or C₁-C₆ alkoxy, to give a compound of the formula : wherein R¹, R², R³, R⁵, R⁶, X, A and Q are each as defined above, or a salt thereof, or (10) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹¹OH wherein R¹¹ is C₁-C₆ alkyl, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (11) reacting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R¹² wherein R¹² is acyl, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, or (12) reacting a compound of the formula : wherein R³, R⁴, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹³-Z³ wherein R¹³ is C₁-C₆ alkyl, and Z³ is halogen, or a salt thereof, to give a compound of the formula: wherein R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, and continuously reacting it with a compound of the formula : H₂N-Y-NH₂ wherein Y is C₁-C₆ alkylene, or a salt thereof, to give a compound of the formula : wherein R³, R⁴, A, Q and Y are each as defined above, or a salt thereof, or (13) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, to reduction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (14) reacting a compound of the formula : wherein R², R³, R⁴, R¹³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : NH₂R 1 / a wherein R 1 / a is C₁-C₆ alkyl which may have halogen, or a salt thereof, to give a compound of the formula: wherein R 1 / a, R², R³, R⁴, A and Q are each as defined above, or a salt thereof, or (15) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, or (16) subjecting a compound of the formula : wherein R¹, R², R³, R¹¹, A and Q are each as defined above, or a salt thereof, to amidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, or (17) reacting a compound of the formula : wherein R¹, R², R³, R⁷, X¹, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁴NHNH₂ wherein R¹⁴ is hydrogen or C₁-C₆ alkyl, to give a compound of the formula : wherein R1, R², R³, R¹⁴, A and Q are each as defined above, or a salt thereof, or (18) reacting a compound of the formula : wherein R¹, R², R³ and Q are each as defined above, R¹⁵ is C₁-C₆ alkyl, and A¹ is C₁-C₆ alkylene or bond, or a salt thereof, with hydrazine, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (19) reacting a compound of the formula : wherein R1, R², R³, A¹ and Q are each as defined above, or a salt thereof, with S-C₁-C₆ alkylisothiourea or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (20) subjecting a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, to ring closure, to give a compound of the formula : wherein R¹, R², R³, A¹ and Q are each as defined above, or a salt thereof, or (21) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁶-Z⁴ wherein R¹⁶ is thiazolyl substituted with C₁-C₆ alkyl, triazolyl substituted with amino, triazolyl substituted with amino and C₁-C₆ alkyl, benzoisothiazolyl substituted with oxo, or benzothiadiazinyl substituted with oxo, and Z⁴ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁶, A and Q are each as defined above, or a salt thereof, or (22) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / b is furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, or a salt thereof, to oxidation reaction, to give a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / c is furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, or a salt thereof, or (23) reacting a compound of the formula : wherein R1, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : R¹⁷-Z⁵ wherein R¹⁷ is C₁-C₆ alkyl, and Z⁵ is halogen, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, or (24) reacting a compound of the formula : wherein R¹, R², R³, R¹⁷, A and Q are each as defined above, or a salt thereof, with a compound of the formula : H₂N-R5 wherein R⁵ is as defined above, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R⁵, A and Q are each as defined above, or a salt thereof, or (25) subjecting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, and R 4 / d is C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, or a salt thereof, to elimination reaction of C₁-C₆ alkanoyl, to give a compound of the formula : wherein R1, R², R³, A and Q are each as defined above, and R 4 / e is hydroxy(C₁-C₆)alkylureido, or a salt thereof, or (26) reacting a compound of the formula : wherein R¹, R², R³, A and Q are each as defined above, or a salt thereof, with a compound of the formula : wherein R¹⁸ is C₁-C₆ alkyl, and R¹⁹ is carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, benzenesulfonyl, which is substituted with one or more substituent(s) selected from C₁-C₆ alkyl, C₁-C₆ alkoxy, halogen and amino, or mono or di(C₁-C₆)alkylsulfamoyl, or a salt thereof, to give a compound of the formula: wherein R¹, R², R³, R¹⁹, A and Q are each as defined above, or a salt thereof, or (27) subjecting a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof, to hydrolysis, to give a compound of the formula : wherein R¹, R², R³, R¹², A and Q are each as defined above, or a salt thereof. A process according to claim 1, wherein R¹ and R² are each hydrogen, C₁-C₆ alkyl or trihalo(C₁-C₆)alkyl; or R¹ and R² are linked together to form C₁-C₆ alkylene, R⁴ is amino, carbamoyl, aminocarbamoyl, guanidinocarbamoyl, C₁-C₆ alkylcarbamoyl, sulfamoylaminocarbonyl, C₁-C₆ alkoxycarbonyl, ureido, thioureido, sulfamoylamino, C₁-C₆ alkanoylamino, C₁-C₆ alkoxycarbonylamino, C₁-C₆ alkylsulfonylamino, C₁-C₆ alkoxy(C₁-C₆)alkanoylamino, C₁-C₆ alkanoyloxy(C₁-C₆)alkanoylamino, C₁-C₆ alkylthio(C₁-C₆)alkanoylamino, nitrobenzoylamino, furoylamino, thenoylamino, nicotinoylamino, 1-oxonicotinoylamino, morpholinocarbonylamino, 3-C₁-C₆ alkylureido, 3-C₁-C₆ alkylthioureido, 3-C₁-C₆ alkanoylureido, 3-allylureido, 3-benzoylthioureido, furyl(C₁-C₆)alkylthio(C₁-C₆)alkanoylamino, furyl(C₁-C₆)alkylsulfinyl(C₁-C₆)alkanoylamino, mono or di(C₁-C₆)alkylsulfamoylamino, 3-hydroxy(C₁-C₆)alkylureido, 3-C₁-C₆ alkanoyloxy(C₁-C₆)alkylureido, 2-C₁-C₆ alkylisothioureido, thiazolylamino substituted with C₁-C₆ alkyl, triazolylamino substituted with amino, triazolylamino substituted with amino and C₁-C₆ alkyl, benzoisothiazolylamino substituted with oxo, benzothiadiazinylamino substituted with oxo and halogen, pyrimidinyl substituted with oxo and C₁-C₆ alkyl, triazolyl substituted with amino, or a group of the formula : wherein n, X and R⁶ are as defined in claim 1, R5 is hydrogen, cyano, nitro, carbamoyl, C₁-C₆ alkoxycarbonyl, sulfamoyl, C₁-C₆ alkylsulfonyl, phenylsulfonyl substituted with C₁-C₆ alkyl, phenylsulfonyl substituted with C₁-C₆ alkoxy, phenylsulfonyl substituted with halogen, phenylsulfonyl substituted with amino, mono or di(C₁-C₆)alkylsulfamoyl, A is as defined in claim 1 ; or A-R⁴ is as defined in claim 1, and R³ and Q are each as defined in claim 1. A process according to claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is a group of the formula : wherein R⁵ is sulfamoyl, and R⁶ is amino, A is C₁-C₆ alkylene, and Q is hydrogen. A process according to claim 2, wherein R¹ and R² are each hydrogen, R³ is hydrogen, R⁴ is ureido or 3-C₁-C₆ alkylureido, A is C₁-C₆ alkylene, and Q is hydrogen. A process for the manufacture of a pharmaceutical composition comprising as an active ingredient a compound of formula I according to claim 1 characterized by mixing a compound of formula I with at least one pharmaceutically acceptable non-toxic carrier or excipient. Modification of the process claimed in claim 1 which is characterized by bringing a compound of the formula I or a non-toxic salt thereof produced by a process claimed in claim 1, into pharmaceutically acceptable form by admixture or presentation of said compound with a pharmaceutically acceptable diluent or carrier. Use of a compound I according to claim 1 for the manufacture of a medicament for therapeutic treatment of ulcer in human beings or animals.

Inventors: INOUE YOSHIKAZU, KATSURA YOUSUKE, TAKASUGI HISASHI, TOMISHI TETSUO, INOUE, YOSHIKAZU, KATSURA, YOUSUKE, TAKASUGI, HISASHI, TOMISHI, TETSUO
Applicants: FUJISAWA PHARMACEUTICAL CO, FUJISAWA PHARMACEUTICAL CO., LTD.
Application year: 1989
Main classification: C07D417
IPC codes: A61P43, A61K31, A61P1, C07D417