NEW CEPHEM COMPOUNDS AND PROCESSES FOR PREPARATION THEREOF

Abstract: New cephem compounds of the formula: wherein R¹ is amino or a protected amino group; R² is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo(lower)alkyl or cyclo(lower)alkenyl; and R³ is a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)­ alkyl, protected amino(lower)alkyl, amino(lower)alkyl, carboxy(lower)alkyl and hydroxyimino(lower)alkyl; and pharmaceutically acceptable salts thereof, and process for their preparation, and also a pharmaceutical composi­ tion comprising, as an effective ingredient, the above com­ pound in association with a pharmaceutically acceptable, substantially nontoxic carrier or excipient. The invention also relates to the starting compounds. and their preparation.

Description: NEW CEPHEM COMPOUNDS AND PROCESSES FOR PREPARATION THEREOF The present invention relates to new cephem compounds and pharmaceutically acceptable salts thereof. More particularly, it relates to new cephem compounds and pharmaceutically acceptable salts thereof, which have antimicrobial activities and to processes for preparation thereof, to pharmaceutical composition comprising the same, and to a method of using the same therapeutically in the treatment of infectious diseases in human being and animals. Accordingly, it is one object of the present invention to provide new cephem compounds and pharmaceutically acceptable salts thereof, which are active against a number of pathogenic microorganisms. Another object of the present invention is to provide processes for the preparation of new cephem compounds and pharmaceutically acceptable salts thereof. A further object of the present invention is to provide pharmaceutical composition comprising, as active ingredients, said new cephem compounds and pharmaceutically acceptable salts thereof. Still further object of the present invention is to provide a method for the treatment of infectious diseases caused by pathogenic bacteria in human being and animals. The object new cephem compounds are novel and can be represented by the following general formula (I). EMI2.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cycloClower)alkyl or cyclo(lower)alkenyl; and R3 is a thiazolio group which may be sub stituted with suitable substituent(s) or a pyridinio group substituted with sub stituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower aikanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo (lower) alkyl, protected amino (lower) alkyl, amino (lower) alkyl, carboxy (lower) alkyl and hydroxyimino (lower) alkyl. According to the present invention, the new cephem compounds (I) can be prepared by various processes which are illustrated in the following scheme. Process 1 EMI3.1 or a salt thereof EMI3.2 or a salt thereof Process 2 EMI3.3 or a salt thereof EMI3.4 or a salt thereof Process 3 EMI4.1 or its reactive derivative or its reactive derivative at the amino group or a at the carboxy group salt thereof. or a salt thereof EMI4.2 or a salt thereof @@@@@@@ 4 EMI4.3 Process 5 EMI5.1 or a salt thereof wherein R1, R2 and R3 are each as defined above; R4 is a group which can be substituted with a group of the formula: R wherein R3 is as defined above; R3a is thiazole which may be substituted with suitable substituent(s) or pyridine substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, acylamino,amino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxyClower)alkyl, sulfo(lower)alkyl, protected amino(lower) alkyl, amino (lower) alkyl, carboxy (lower) - alkyl and hydroxyimino(lower)alkyl; R3b is a pyridinio group substituted with protected amino (lower) alkyl; R3c is a pyriGinio group substituted with amino(lower)alkyl; R2a is protected carboxy(lower)alkyl; R2b is carboxy(lower)alkyl; R5 is a protected carboxy group; and X is an acid residue. Among the starting compounds of the present invention, the compound (VI) is novel and can be prepared by the following methods. EMI6.1 or its reactive derivative or its reactive derivative at the carboxy group or a at the amino group or a salt salt thereof thereof EMI6.2 wherein R1 R2 R3 R3a R5 and X are each as defined above. Regarding the object compounds (I), (Ia), (Ib), (Ic) and (Id) and the starting compounds (II), (V), (VIII). (VI), (IX) and (X), it is to be understood that said object and starting compounds include syn isomer, anti isomer and a mixture thereof. For example, with regard to the object compound (I), syn isomer means one geometrical isomer having the partial structure represented by the following formula: EMI7.1 (wherein RÚ and Rê are each as defined above) and anti isomer means the other geometrical isomer having the partial structure represented by the following formula: EMI8.1 (wherein R1 and R2 are each as defined above). Regarding the other object compounds and statring compounds as mentioned above, the syn isomer and the anti isomer can also be referred to the same geometrical isomers as illustrated for the compound (I). Suitable pharmaceutically acceptable salts of the object compounds (I) are conventional non-toxic salt and include a metal salt such as an alkali metal salt (e.g. sodium salt, potassium salt, etc.) and an alkaline earth metal salt (e.g. calcium salt, magnesium salt, etc.), an ammonium salt, an organic base salt (e.g. trimethylamine salt, triethylamine salt, pyridine salt, picoline salt, dicyclohexylamine salt, N,N'dibenzylethylenediamine salt, etc.), an organic acid salt (e.g. acetate, maleate, tartrate, methanesulfonate, benzenesulfonate, formate, toluenesulfonate, etc.), an inorganic acid salt (e.g. hydrochloride, hydrobromide, hydroiodide, sulfate, phosphate, etc.), or a salt with an amino acid (e.g. arginine, aspartic acid, glutamic acid, etc.), and the like. In the above and subsequent descriptions of the present specification, suitable examples and illustrations of the various definitions which the present invention include within the scope thereof are explained in details as follows. The term "lower" is intended to mean 1 to 6 carbon atoms, unless otherwise indicated. Suitable "protected amino" for R1 and "protected amino" moiety in the term "protected amino (lower) alkyl" may include an acylamino or an amino group substituted by a conventional protecting group such as ar(lower)alkyl which may have at least one suitable substituent(s), (e.g. benzyl, trityl, etc.) or the like. Suitable acyl moiety in the term "acylamino" may include carbamoyl, aliphatic acyl group and acyl group containing an aromatic or heterocyclic ring. And, suitable examples of the said acyl may be lower alkanoyl (e.g. formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, oxalyl, succinyl, pivaloyl, etc.); lower alkoxycarbonyl having 2 to 7 carbon atoms (e.g. methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, l-cyclopropylethoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, tertiarybutoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, etc.); lower alkanesulfonyl (e.g. mesyl, ethanesulfonyl, propanesulfonyl, isopropanesulfonyl, butanesulfonyl, etc.); arenesulfonyl (e.g. benzenesulfonyl, tosyl, etc.); aroyl (e.g. benzoyl, toluoyl, xyloyl, naphthoyl, phthaloyl, indancarbonyl, etc.); ar(lower)alkanoyl (e.g. phenylacetyl, phenylpropionyl, etc.); ar (lower) alkoxycarbonyl (e. g. benzyloxycarbonyl, phenethyloxycarbonyl, etc.), and the like. The acyl moiety as stated above may have at least one suitable substituent(s) such as halogen (chlorine, bromine, fluorine and iodine), lower alkanoyl or the like. Suitable lower aliphatic hydrocarbon group may include lower alkyl, lower alkenyl, lower alkynyl and the like. Suitable "cyclo(lower)alkyl" for R2 may include one having 3 to 6 carbon atoms, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or the like, preferably one having 4 to 6 carbon atoms. Suitable "cyclo(lower)alkenyl"for R2 may include one having 3 to 6 carbon atoms, for example, cyclopentenyl, cyclohexenyl or the like, preferably one having 5 to 6 carbon atoms. Suitable "lower alkyl" and "lower alkyl" moiety in the terms "hydroxy(lower)alkylt',"sulfoflower)alkyl", "protected amino(lower) alkyl", "hydroxyimino (lower) - alkyl" ,"amino (lower) alkyl", "protected carboxy (lower) alkyl" and "carboxy(lower)alkyl" is one having 1 to 6 carbon atom(s) and may include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, tertpentyl, hexyl and the like, and preferably one having 1 to 4 carbon atom(s). Suitable "lower alkenyl" is one having 2 to 6 carbon atoms and may include vinyl, allyl, isopropenyl, l-propenyl, 2-butenyl, 3-pentenyl and the like. Suitable "lower alkynyl" is one having 2 to 6 carbon atoms and may include ethynyl, 2-propynyl, 2-butynyl, 3-pentynyl, 3-hexynyl and the like. The lower aliphatic hydrocarbon group as mentioned above may be substituted with lto 3 suitable s.ubstituentCs) such as carboxy, protected carboxy as mentioned below, halogen (e.g. chlorine, bromine, etc.) or the like. Suitable substituent(s) on a thiazolio group for R3 and thiazole for R3a may include lower alkyl (e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, tert-pentyl, hexyl, etc.), hydroxy (lower) alkyl (e.g. hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, etc.) and the like, and the number of the substituent(s) may be 1 to 3. A pyridinio group for R or pyridine for R a is substituted with 1 to 3 substituent(s) as mentioned above. Suitable "halogen" may include chlorine, bromine, fluorine and iodine. Suitable "lower alkanoyl" can be referred to the ones as exemplified for aforesaid "acyl". Suitable "alkyl" moiety in the term "alkylcarbamoyl1, is one having 1 to 14 carbon atom(s) and may include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, t-pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl and the like, preferably one having 1 to 12 carbon atom(s). Suitable "protected carboxy" and "protected carboxy" moiety in the term "protected carboxy(lower)alkyl" may include esterified carboxy in which said .ester may be the ones such as alkyl ester (e.g. methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, t-butyl ester, pentyl ester, t-pentyl ester, hexyl ester, heptyl ester, octyl ester, nonyl ester, decyl ester, undecyl ester, dodecyl ester,hexadecyl ester, etc.) lower alkenyl ester (e.g. vinyl ester, allyl ester, etc.); lower alkynyl ester (e.g. ethynyl ester, propynyl ester, etc.); mono(or di or tri)-halo (lower)alkyl ester (e.g., 2-iodoethyl ester, 2,2,2- trichloroethyl ester, etc.); lower alkanoyloxy(lower)alkyl ester (e.g. acetoxymethyl ester, propionyloxymethyl ester, l-acetoxypropyl ester, valeryloxymethyl ester, pivaloyloxymethyl ester, hexanoyloxymethyi ester, l-acetoxyethyl ester, 2-propionyloxyethyl ester, l-isobutyryloxyethyl ester, etc.); lower alkanesulfonyl(lower)alkyl ester (e.g., mesylmethyl ester, 2-mesylethyl ester, etc.); ar(lower)alkyl ester, for example, phenyl(lower)alkyl ester which may be substituted with one or more suitable substituent(s) (e.g. benzyl ester, 4-methoxybenzyl ester, 4-nitrobenzyl ester, phenethyl ester, trityl ester, diphenylmethyl ester, bis(methoxyphenyl)methyl ester, 3,4-dimethoxybenzyl ester, 4-hydroxy-3,5 ditertiarybutylbenzyl ester, etc.); lower alkoxycarbonyloxy(lower)alkyl ester (e.g. methoxycarbonyloxymethyl ester, ethoxycarbonyloxymethyl ester, ethoxycarbonyloxyethyl ester, etc.) which may be substituted with azido; a heterocyclic ester, preferably benzotetrahydrofuryl ester which may be substituted with oxo group, more preferably phthalidyl ester; aroyloxy(lower)alkyl ester (e.g. benzoyloxymethyl ester, benzoyloxyethyl ester, toluoyloxyethyl ester, etc.); aryl ester which may have one or more suitable substituent(s) (e.g. phenyl ester, tolyl ester, tertiarybutylphenyl ester, xylyl ester, mesityl ester, cumenyl ester, etc.), and the like. Preferable example of "protected carboxy" may be alkoxycarbonyl (e.g. methoxycarbonyl, e thoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, t-butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl, hexadecyloxycarbonyl, etc.). Suitable R4 may include an acid residue such as acyloxy, azido, halogen or the like, wherein acyl moiety in the term "acyloxy" and halogen can be referred to the ones as exemplified above. Suitable X may include acid residue as above. Preferred embodiments of the object compound (I) are as follows. Preferred embodiment of R1 is amino; R2 is lower alkyl (most preferably ethyl), cyclo(lower)alkyl (most preferably cyclopentyl), cyclo(lower)alkenyl (most preferably cyclopentenyl), carboxyClower)alkyl or esterified carboxy (lower) alkyl (more preferably lower alkoxycarbonyl(lower)alkyl); ; R3 is thiazolio, thiazolio substituted with lower alkyl and hydroxy(lower)alkyl, or pyridinio substituted with 1 to 2 substituent(s) selected from the group consisting of halogen, cyano, hydroxy, lower alkanoyl (most preferably acetyl), acylamino (more preferably lower alkanesulfonylamino, most preferably mesylamino), amino, hydroxycarbamoyl, alkylcarbamoyl, carboxy, alkoxycarbonyl, lower alkyl, hydroxy(lower)alkyl, carboxy(lower)alkyl, amino (lower) alkyl, lower alkoxycarbonylamino (lower) alkyl, sulfo (lower) alkyl and hydroxyimino (lowe;r) alkyl. The processes for preparing the object compounds of the present invention are explained in details 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). Suitable salt of the compound (II) can be referred to the ones exemplified for the compound (I). The present reaction may be carried out in a solvent such as water, phosphate buffer, acetone, chloroform, acetonitrile, nitrobenzene, methylene chloride, ethylene chloride, formamide, dimethylformamide, methanol, ethanol, ether, tetahydrofuran, diRethylsulfoxide, or any other organic solvent which does not- adversely affect the reaction, preferably in ones having strong polarities. Among the solvents, hydrophilic solvents may be used in a mixture with water. The reaction is preferably carried out in around neutral medium. When the compound (II) is used in a free form, the reaction is preferably conducted in the presence of a base, for example, inorganic base such as alkali metal hydroxide, alkali metal carbonate, alkali metal bicarbonate, organic base such as trialkylamine, and the like. The reaction temperature is not critical, and the reaction is usually carried out at ambient temperature, under waring or under heating. The present reaction is preferably carried out in the presence of alkali metal halide (e.g. sodium iodide, potassium iodide, etc.), alkali metal thiocyanate (e.g. sodium thiocyanate, potassium thiocyanate, etc.) etc. Process 2 The object compound (Ib) or a salt thereof can be prepared by subjecting the compound (Ia) or a salt thereof to elimination reactiDn of the protective group of amino. Suitable salts of the. compounds (Ia) and (Ib) can be referred to the ones exemplified for the compound (I). The present elimination reaction is carried out in accordance with a conventional method such as hydrolysis; reduction; a method by reacting the compound (Ia) wherein the protective group is acyl group with iminohalogenating agent and then with iminoetherifying agent, and, if necessary, subjecting the resulting compound to hydrolysis; or the like. The hydrolysis may include a method using an acid or base or hydrazine and the like. These methods may be selected depending on the kind of the protective groups to be eliminated. Among these methods, hydrolysis using an acid is one of the common and preferable method for eliminating the protective group such as substituted or unsubstituted alkoxycarbonyl (e.g. t-pentyloxycarbonyl, t-butoxycarbonyl, etc.), alkanoyl (e.g. formyl, etc.), cycloalkoxycarbonyl, substituted or unsubstituted aralkoxycarbonyl (e.g. benzyloxycarbonyl, substituted benzyloxycarbonyl, etc.), ar(lower)alkyl (e.g. benzyl, trityl, etc.) or the like. Suitable acid may include an organic or an inorganic acid, for example, formic acid, trifluoroacetic acid, benzenesulfonic acid, p-toluenesulfonic acid, hydrochloric acid and the like, and preferable acid is, for example, formic acid, trifluoroacetic acid, hydrochloric acid, etc. The acid suitable for the reaction can be selected according to the kind of protective group to be eliminated. When the elimination reaction is conducted with the acid, it can be carried out in the presence or absence of a solvent. Suitable solvent may include a conventional organic solvent, water or a mixture thereof. When trifluoroacetic acid is ued, the elimination reaction may preferably be carried out in the presence of anisole. The hydrolysis using hydrazine is commonly applied for eliminating the protective group, for example, succinyl or phthaloyl. The hydrolysis with a base is preferably applied for eliminating acyl group, for example, haloalkanoyl (e.g. dichloroacetyl, trifluoroacetyl, etc.) etc. Suitable base may include, for example, an inorganic base such as alkali metal hydroxide (e.g. sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal hydroxide (e.g. magnesium hydroxide, calcium hydroxide, etc.), alkali metal carbonate (e.g. sodium carbonate, potassium carbonate, etc.), alkaline earth metal carbpnate (e.g. magnesium carbonate, calcium carbonate, etc.), alkali metal bicarbonate (e.g. sodium bicarbonate, potassium bicarbonate, etc.), alkali metal acetate (e.g. sodium acetate, potassium acetate, etc.), alkaline earth metal phosphate (e.g. magnesium phosphate, calcium phosphate, etc.), alkali metal hydrogen phosphate (e.g. disodium hydrogen phosphate, dipotassium hydrogen phosphate, etc.), or the like, and an organic base such as trialkylamine (e.g. trimethylamine, triethylamine, etc.), picoline, N-methylpyrrolidine, N methylmorpholine, l,5-diazabicyclo4,3,0)- non-5-ene, l-4-diazabicyclo[2,2,2)octane, 1,5-diazabi cyclo[5,4,0)undecene-Sor the like. The hydrolysis using a base is often carried out in water, a conventional organic solvent or a mixture thereof. Among the protective group, the acyl-group can be generally eliminated by hydrolysis as mentioned above or by the other conventional hydrolysis. In case that the acyl group is halogen substituted-alkoxycarbonyl or 8-quinolyloxycarbonyl, they are eliminated by treating with a heavy metal such as copper, zinc or the like. The reductive elimination is generally applied for eliminating the protective group, for example, haloalkoxycarbonyl (e.g. trichloroethoxycarbonyl, etc.), substituted or unsubstituted aralkoxycarbonyl (e.g. benzyloxycarbonyl, substituted benzyloxycarbonyl etc.), 2-pyridylmethoxycarbonyl, etc. Suitable reduction may include, for example, reduction with an alkali metal borohydride (e.g. sodium borohydride, etc.) and the like. The reaction temperature is not critical and may be suitably selected in accordance with the kind of the protective group of the amino group and the elimination method as mentioned above, and the present reaction is preferably carried out under a mild condition such as under cooling, at ambient temperature or slightly elevated temperature. The present reaction includes, within its scope, the cases that the protected amino group for R1 is transformed into the free amino group in the course of the elimination reaction as mentioned above or in the post-treatment of the reaction mixture of reaction product. Process 3 The object compound (I) or a salt thereof can be prepared by reacting the compound (IV) or its reactive derivative at the amino group or a salt thereof with the compound CV) or its reactive derivative at the carboxy group or a salt thereof. Suitable reactive derivative at the amino group of the compound (IV) may include conventional reactive derivative used in amidation, for example, Schiff's base type imino or its tautomeric enamine type isomer formed by the reaction of the compound (IV) with a carbonyl compound; a silyl derivative formed by the reaction of the compound CIV) with a silyl compound such as bisCtrimethylslyl)acetamide, trimethylsilylacetamide or the like; a derivative formed by reaction of the compound (IV) with phosphorus trichloride or phosgene, and the like. Suitable salt of the compound (IV) may include an acid addition salt such as an organic acid salt (e.g. acetate, maleate, tartrate, benzenesulfonate, toluenesulfonate, etc,) or an inorganic acid salt (e.g. hydrochloride, hydrobromide, sulfate, phosphate, etc.); a metal salt (e.g. sodium salt, potassium salt, calcium salt, magnesium salt, etc.); ammonium salt; an organic amine salt (e.g. triethylamine salt, dicyclohexylamine salt, etc.), and the like. Suitable reactive derivative at the carboxy group of the compound (V) may include an acid halide, an acid anhydride, an activated amide, an activated ester, and the like. The suitable example may be an acid chloride; an acid azide; a mixed acid anhydride with an acid such as substituted phosphoric acid (e.g. dialkylphosphoric acid, phenylphosphoric acid, diphenylphosphoric acid, dibenzylphosphoric acid, hálogenated phosphoric acid, etc.), dialkylphosphorous acid, sulfurous acid, thiosulfuric acid, sulfuric acid, alkylcarbonic acid, aliphatic carboxylic acid Ce.g. pivalic acid, pentanoic acid, isopentanoic acid, 2-ethylbutyric acid, acetic acid or trichloroacetic acid, etc.) or aromatic carboxylic acid (e.g. benzoic acid, etc.); a symmetrical acid anhydride; an activated amide with imidazole, dimethylpyrazole, triazole or tetrazole; or an activated ester (e.g. cyanomethyl ester, methoxymethyl ester, dimethyliminomethyl [(CH3)2N+ = CH-J ester, vinyl ester, propargyl ester, p-nitrophenyl ester, 2,4-dinitrophenyl ester, trichlorophenyl ester, pentachlorophenyl ester, mesyl phenyl ester, phenylazophenyl ester, phenyl thioester, pnitrophenyl thioester, p-cresyl thioester, carboxymethyl thioester, pyranyl ester, pyridyl ester, piperidyl ester, 8-quinolyl thioester, or an ester with N,Ndimethylhydroxylamine, l-hydroxy-2- (lH) -pyridone, Nhydroxysuccinimide, N-hydroxyphthalimide or 1hydroxy 6-chloro-lH-benzotriazole, and the like. These reactive derivatives can be optionally selected from them according to the kind of the compound CV) to be used. The salts of the compound (V) may be salts with an inorganic base such as an alkali metal salts (e.g. sodium or potassium salt), or an alkaline earth metal salt (e.g. calcium or magnesium salt), a salt with an organic base such as trimethylamine, triethylamine, pyridine, a salt with an acid (e.g. hydrochloric acid or hydrobromic acid) or the like. The reaction is usually carried out in a conventional solvent such as water, 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 to the reaction. Among these solvents, hydrophilic solvents may be used in a mixture with water. When the compound (V) is used in free acid form or its salt form in the reaction, the reaction is preferably carried out in the presence of a conventional condensing agent such as N,N-dicyclohexylcarbodiimide; N-cyclohexyl-N' -morpholinoethylcarbodiimide; N-cyclohexyl-N'-(4-diethylaminocyclohexyl)carbodiimide; N,N diethylcarbodiimide; N,N,diisopropylcarbodiimide; Nethyl-N'-(3-dimethylaminopropyl)carbodiimide; N,Ncarbonylbis(2-methylimidazole); pentamethylene-ketene N-cyclohexylimine; diphenylketene-N-cyclohexylimine; ethoxyacetylene; ethyl polyphosphate; isopropyl polyphosphate; diethyl phosphorochloridite; phosphorus oxychloride; phosphorus trichloride; phosphorus pentachloride; thionyl chloride; oxalyl chloride; triphenylphosphine; N-ethyl-7-hydroxybenzisoxazolium fluoroborate; N-ethyl-S-phenylisoxazolium-3' -sulfonate; l-(p-chlorobenzenesulfonyloxy)-6-chloro-lH-benzotriazole; so-called Vilsmeier reagent, for example (chloromethylene) dimethylammonium chloride produced by the reaction of dimethylformamide with thionyl chloride or phosgene, a compound produced by the reaction of dimethylformamide with phosphorus oxychloride, etc.; or the like. The reaction may be also carried out in the presence of an inorganic or an organic base such as an alkali metal hydroxide, an alkali metal bicarbonate, alkali metal carbonate, alkali metal acetate, triClower)alkylamine, pyridine, N- (lower)alkylmorpholine, N,N-di (lower) alkYlbenzylamine, N,N-diClower)alkylaniline as exemplified below, or the like. When the base or the condensing agent is in liquid, it can be used also as a solvent. The reaction temperature is not critical, and the reaction is usually carried out under cooling or at ambient temperature. In the present reaction, a syn-isomer of the object compound (I) can be obtained preferably by conducting the reaction of the compound (IV) with a syn- isomer of the starting compound (V). Process 4 The object compound (Id) or a salt thereof can be prepared by subjecting the compound (Ic) or a salt thereof to elimination reaction of the protective group of carboxy. Suitable salt of the compounds (Ic) and (Id) can be referred to the ones exemplified for the compound (I). The present reaction is carried out in accordance with a conventional method such as hydrolysis, reduction or the like. In case that the protective group is an ester, the protective group can be eliminated by hydrolysis. Hydrolysis is preferably carried out in the presence of a base or an acid. Suitable base may include an inorganic base and an organic base such as an alkali metal (e.g. sodium, potassium, etc.), an alkaline earth metal (e.g. magnesium, calcium, etc.), the hydroxide or carbonate or bicarbonate thereof, trialkylamine (e.g. trimethylamine, triethylamine, etc.), picoline, 1,5-diazabicyclo[4,3,0]none-5-ene, 1,4-diazabicyclo[2, 2,2)octane, 1,8-diazabicyclot5a4,0]undecene*7, or the like. Suitable acid may include an organic acid (e.g. formic acid, acetic acid, propionic acid, trifluoroacetic acid, etc.) and an inorganic acid (e.g. hydrochloric acid, hydrobromic acid, sulfuric acid, etc.). The reaction is usually carried out in a sol- vent such as water, an alcohol (e.g. methanol, ethanol, etc,), a mixture thereof or any other solvent which does not adversely influence to the reaction. A liquid base or acid can be also used as the solvent. The reaction temperature is not critical and the reaction is usually carried out under cooling to warming. Reduction can be applied preferably for elimination of the protective group such as 4-nitrobenzyl, 2 iodoethyl, 2,2,2-trichloroethyl, or the like. The reduction method applicable for the elimination reaction may include, for example, reduction by using a combination of a metal (e.g. zinc, zinc amalgam, etc.) or a salt of chrome compound (e.g. chromous chloride, chromous acetate, etc.) and an organic or inorganic acid (e.g. acetic acid, propionic acid, hydrochloric acid, etc.); and conventional catalytic reduction in the presence of a conventional metallic catalyst (e.g. palladium-carbon, etc.). Process 5 The compound (I) or a salt thereof can be prepared by subjecting the compound (VI) to elimination reaction of carboxy-protective group. The present elimination reaction can be carried out according to a similar manner to that of Process 4. The Preparations of the starting compound(VI) are explained in detail in the following. Preparation 1 The compound (VIII) can be prepared by reacting the compound (V) or its reactive derivative at the carboxy group or a salt thereof with the compound (VII) or its reactive derivative at the amino group or a salt thereof. The present reaction can be carried out in a similar manner to that of Process 3. Preparation 2 The compound (IX) or a salt thereof can be prepared by oxidizing the compound (VIII) or a salt thereof. Suitable oxidizing agent to be used in this reaction may include all oxidizing agenthich can oxidize -S- group in cephalosporin compounds to group, for example, peroxide (e.g., hydrogen peroxide, 3-chloroperbenzoic acid, etc.) and the like. The reaction is usually carried out in solvent such as methylene chloride or any other solvent which does not adversely affect the reaction. The reaction temperature is not critical and preferably under cooling or at ambient temperature. Preparation 3 The compound (X) can be prepared by reacting the 3a compound (IX) or a salt thereof with the compound R The reaction can be carried out according to a similar manner to that of Process 1. Preparation 4 The compound (VI) can be prepared by reducing the compound (X). The present reduction can be carried out in fhe presence of conventional reducing agent which can reduce -S- group in cephalosporin compound to -S- group, for example, phosphorus halide such as phosphorus trihalide (e.g, phosphorus trichlo ride, etc.). The object compound (I) of the present invention exhibits high antimicrobial activity and inhibits the growth of a number of microorganisms including pathogenic Gram-positive and Gram-negative bacteria. For therapeutic administration, the cephalosporin compounds according to the present invention are used in the form of pharmaceutical preparation which contain said compounds in admixture with a pharmaceutically acceptable carriers such as an organic or inorganic solid or liquid excipient suitable for oral, parenteral or external administration. The pharmaceutical preparations may be in solid form such as capsule, tablet, dragee, ointment or suppository, or in liquid form such as solution, suspension, or emulsion. If desired, there may be included in the above prepara tions auxiliary substances, stabilizing agents, wetting or emulsifying agents, buffers and other commonly used additives. lThile the dosage of the compounds may vary from and also depend upon the age and condition of the patient, an average single dose of about 50 mg., 100 mg., 250 mg., and 500 mg. of the compounds according to the present invention has proved to be effective for treating of infectious diseases caused by a number of pathogenic bacteria. In general amounts, daily dose between I mg/body and about lOOQ mg/body or even more may be administered. Now in order to show the utility of the object compounds (I), test data on anti-microbial activity of representative compounds of the present invention are shown below. Test method One loopful of an overnight culture of each test strain in Trypticase-soy broth (108 viable cells per ml.) was streaked on heart infusion agar (HI-agar) containing graded concentrations of antibiotics, and the minimal inhibitory concentration (MIC) was expressed in terms of vg/ml after incubation at 370C for 20 hours. Test compound (1) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-hydroxymethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer) (2) 70E20Ethoxyimino 2-(5-amino-1,2,4 tSiadiazol-30yl)- acetamino]-3-(4-hydroxymethyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer) (3) 7-[2 EtOhoxyimino-2-(5 amino-1,2,4 tSiadiazol-3-yl)- acetamindo]-3-(3-chloro-1-pyridiniomethyl)-5 cephem-4-carboxylate (syn isomer) (4) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl] acetamino]-3-[3,5-dimethyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer) (5) 7-[2-Ethoximino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-[4-(3-hydroxypropyl)-1-pyridiniomethyl] 3-cephem-4-carboxylate (syn isomer) Test Results EMI24.1 <tb> Test <SEP> Bacteria <SEP> Test <SEP> Compound <tb> <SEP> (1) <SEP> (2) <SEP> (3) <SEP> (4) <SEP> (5) <tb> <SEP> MIC(ug/ml) <tb> B. <SEP> subtilis <SEP> ATCC <SEP> 6633 <SEP> 0.78 <SEP> 0.78 <SEP> 0.78 <SEP> 1.56 <SEP> 0.78 <tb> Ps. <SEP> aeruginosa <SEP> 2 <SEP> 6.25 <SEP> 12.50 <SEP> 6.25 <SEP> 6.25 <SEP> 12.50 <tb> S. <SEP> marcascens <SEP> 35 <SEP> 3.13 <SEP> 1.56 <SEP> 3.13 <SEP> 3.13 <SEP> 1.56 <tb> The following Preparations and Examples are given for the purpose of illustrating the present invention. Preparation 1 To a suspension of isonicotinoyl chloride hydrochloride (8.94 g) in methylene chloride (50 ml) was dropped a solution of t-butylamine ±11.0 g) in methylene chloride (30 ml) over 70 minutes below 400C under stirring. The mixture was stirred, for 4 hours at ambient temperature and poured into water. After the mixture was adjusted to pH 7.5 with aqueous sodium bicarbonate, the organic layer was separated out, washed with water, dried over magnesium sulfate and evaporated to dryness to give N-t-butylisonicotinamide (6.8 g), mp. 1150C to 1170C. IR ±Nujol) : 3270, 1638, 1595, 1544, 1317, 1210 cm 1 NMR (DMSO-d6, d) : 1.40 (9H, s), 7.7 (2H, m), 8.05 1H, bs), 8.7 (2H, m) Prepar-ation 2 The following compounds were obtained according to a similar manner to that of Preparation 1. (I) N-Octylisonicotinamide, mp 61 to 630C. IR (Nujol) : 3290, 1630, 1595, 1538, 1310, 1290 cm-Ú (2) N-Dodecylisonicotinamide, mp 71 to 74 C IR (Nujol) : 3400, 3320, 1630, 1598, 1535 cm 1 Preparation 3 A mixture of isonicotinoyl chloride hydrochloride (17.8 g), t-butylalcohol (14.8 g) and 4-(N,Ndimethylamino)pyridine (122 mg) in methylene chloride (200 ml)-was refluxed for 6 hours. The mixture was washed with aqueous sodium bicarbonate and water, dried over magnesium sulfate and evaporated to give oily t-butyl isonicotinate (8.3 g). IR (film) : 2950, 2830, 1720, 1580, 1560, 1410, 1365, 1320, 1290, 1145, 1120 NMR (DMSO-d6, d) : 1.42 (9H, s), 7.7 (2H, m), 8.7 (2H, m) Preparation 4 A mixture of N-hydroxyphthalimide (58.2 g), l-chloro-2-cyclopentene (36.9 g), triethylamine (53.9 g) in acetonitrile (370 ml) was stirred to give N-(2cyclopenten-l-yloxy)phthalimide (56.5 g) IR (Nujol) : 1780, 1730, 1610 cm NMR (DMSO-d, 8) : 7.92 (4H, s), 6.28 (1H. m), 6.00 (1H, m), 5.42 (1H, m), 2.9-1.98 (4H, m) Preparation 5 (1) A mixture of N-(2-cyclopenten-l-yloxy)phthalimide (22.9 g) and hydrazine hydrate (4,75 g) in ethanol (115 ml) was refluxed for 5 minutes. The reaction mixture was filtered. The filtrate containing (2-cyclopenten-l-yl)oxyamine was added to a solution of sodium 2-(5-formamido-1,2,4 thiadiazol-3-yl)glyoxylate (22.4 g) in water. The mixture was adjusted to pH 2 with 10% hydrochloric acid, stirred for 2 hours and then concentrated. The concentrate was adjusted to pH 1 with 10% hydrochloric acid. The precipitates were collected by filtration and dried to give 2- (2-cyclopenten-1-yl)oxyimino-2- (5-formamido-1,2,4-thiadiazol-3-yl)acetic acid (syn isomer) (20.0 g), mp 1500C (dec.). IR (Nujol) : 3400, 3100, 1720, 1690, 1540 cm 1 NMR (DMSO-d6, 6) : 1.80-2.50 (4H, m), 5.30 5.50 (1H, m), 5.83-6.30 (2H, m), 8.90 (lH, s) (2) To a solution of sodium hydroxide (11.2 g) in water (140 ml) was added S-methyl 2-(5-formamido-1,2,4 thiadiazol-3-yl)thioglyoxylate (27 g) at 10 C and the mixture was stirred for 30 minutes at 20 C. The reaction mixture containing sodium 2-(5-formamido 1,2,4-thiadiazol-3-yl)glyoxylate was cooled, adjusted to pH 7 with 10% hydrochloric acid and thereto was added a solution of cyclopentyloxyamine (15.3 g) in ethanol (150 ml). The mixture was adjusted to pH 3 with 108 hydrochloric acid, and stirred for 1.5 hours. The reaction mixture was adjusted to pH 7 with an aqueous solution of sodium bicarbonate and then -evaporated to remove ethanol. The residue was washed with ethyl acetate. To the aqueous layer was added ethyl acetate and the mixture was adjusted to pH 1 with 10 hydrochloric acid. The precipitates were collected by filtration to give 2-cyclopentyloxyimino-2-(5-formamido-1,2,4-thiadiazo-3-yl)acetic acid (syn isomer) (3.99 g), The filtrate was extracted with ethyl acetate and the extract was dried over magnesium sulfate and then concentrated. The precipitates were collected by filtration and washed with diethyl ether to give the same object compound C8.l g). Total yield : 12.09 g, mp 180 to 185 C Cdec.). IR (Nujol) : 3130, 3040, 2680, 2610, 2520, 1720, 1690, 1660, 1600, 1550 cm NMR (DMSO-d6, ô) : 1.33-2.10 C8H, m), 4.67-5.0 (1H, m), 8.88 (lH, s), 13.50 (1H, s) Preparation 6 A mixture of 2-(2-cyclopenten-1-yl)oxyimino-2(5- formamido-l,2,4-thiadiazol-3-yl)acetic acid (syn isomer) (20.0 g) and 1N aqueous solution of sodium hydroxide (200 ml) was stirred for an hour at 50 to 550C. The reaction mixture was cooled, adjusted to pH 7 with 10% hydrochloric acid and thereto was added ethyl acetate. The mixture was adjusted to pH 1 with 10% hydrochloric acid and extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and evaporated. The residue was pulverized with diisopropyl ether to give 2-(2-cyclopenten-1-yl)oxyimino- 2-(5-amino-1,2,4-thiadiazol-3-yl)acetic acid (syn isomer), mp 1500C (dec.). IR (Nujol) : 3300, 3150, 1710, 1620, 1520 cm 1 NMR (DMSO-d6, 6) : 1.80-2.5Q (4H, m), 5.30-5.50 (lH, m), 5.83-6.30 (2H, m), 8.20 C2H, s) Preparation 7 The following compound was obtained according to a similar manner to that of Preparation 6. 2-Cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetic acid (syn isomer), mp 160 to 1650C (dec.). IR ±Nujol) : 3470, 3290, 3200, 2400, 1715, 1615, 1600, 1520 cm NMR (DMSO-d6, ô) : 1.17-2.10 (8H, m), 4.60-4.97 (lH, m), 8.22 (2H, s) Preparation 8 A mixture of S-methyl(5-formamido-1,2,4-thia diazol-3-yl)thioglyoxylate C6 g) and an aqueous solution (50 ml) of sodium hydroxide (4.2 g) was stirred for an hour at 50 to 550C. The mixture was cooled to ambient temperature and adjusted to pH 7 with 10% hydrochloric acid. On the other hand, a mixture of N- Cethoxycarbonylmethoxy) phthalimide (12.9 g) and hydrazine hydrate C2.08 g) in ethanol (60 ml) was refluxed for 5 minutes and cooled in an ice bath. A resulting precipitate was filtered off and washed with ethanol. The filtrate and the washings were combined and the combined solution containing O-Cethoxycarbonylmethyl)hydroxylamine was added to the above aqueous solution. The mixture was adjusted to pH 3 to 4 with 10% hydrochloric acid and stirred for 1.5 hours at ambient temperature. The solution was neutralized with an aqueous solution of sodium bicarbonate, concentrated to half volume in vacuo and washed with ethyl acetate. The aqueous solution was acidified with 10% hydrochloric acid and extracted with ethyl acetate. The extract was dried over magnesium sulfate, evaporated to dryness and the residue was triturated with diisopropyl ether to give 2-ethoxycarbonyl methoxyimino-2-(5-amino-l,2,4-thiadiazol-3-yl)acetic acid (syn isomer)C1.8 g), mp 135 to 14û C (dec.). IR (Nujol) : 3500,3330,3210,2670,2550,1740, 1610,1540 cm 1 NMR (DMSO-d6, d) : 1.24 (3H, t, J-7Hz), 4.14 (2H, q, J=7Hz): 4.80 (2H, s), 8.15 (2H, broad s) Preparation 9 The following compounds were obtained according to a similar manner to that of Preparation 8. (1) 2-(t-Butoxycarbonylmethoxyimino)-2-(5-amino-1,2,4 thiadiazol-3-yl)acetic acid (syn isomer), mp 150 to 1550C Cdec.). IR (Nujol) : 3420, 3230, 3100, 1725, 1610, 153Q cm 1 NMR CDMSO-d6, 8): 1.45 (9H, s), 4.70 (2H, s), 8.12 (2H, broad s) (2) 2-(1-Ethoxycarbonyl-1-methylethoxyimino)-2-(5-amino l,2,4-thiadiazol-3-yl)acetic acid (syn isomer), mp 165 to 1680C (dec.). IR (Nujol) : 3450, 3350, 3240, 1750, 1730, 1630, 1530 cm NMR (DMSO-d6, 6) : 1.18 (3H, t, J=7Hz), 1.50 (6H, s), 4.15 2H,q, J=7Hz), 8.23 (2H, broad s) Preparation 10 To a cold solution of phosphorus pentachloride (16.6 g) in methylene chloride (150 ml) was added 2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetic acid (syn isomer)(17.3 g) at -180C and the mixture was stirred for 15 minutes at -13 to -100C. On the other hand, a mixture of 7-amino-3-acetoacetoxy- methyl-3-cephem-4-carboxylic acid (25.1 g) and trimethylsilylacetamide (80 g) in methylene chloride (400 ml) was warmed to make a clear solution and cooled to -100C. The cold solution was added to the above activated mixture and the mixture was stirred for 1 hour at -100C. The reaction mixture was poured into an aqueous solution (450 ml) of sodium bicarbonate (42 g) and stirred for l hour at room temperature. The aqueous layer was separated out, adjusted to pH 2 with 6N hydrochloric acid and extracted with ethyl acetate. The extract was washed with water, dried over anhydrous magnesium sulfate and evaporated to dryness. The residue was triturated with diethyl ether to give a powder of 7-[2-ethoxyimino-2-(5- amino-1,2,4-thiadiazol-3-yl)acetamino]-3acetoacetoxymethyl-3-cephem-4-carboxylic acid (syn isomer)(24.5 g). This compound was dissolved in IN methanol solution of sodium acetate (48 ml) and stood on to give precipitates. Thereto was added acetone (100 ml). The precipitates were collected by filtration, washed with acetone to give sodium 7-[2- ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamino]3-acetoacetoxymethyl-3-cephem-4-carboxylate (syn isomer) (19 g). Physical constants of 7-[2-ethoxyimino-2-(5amino-1,2,4-thiadiazol-3-yl)acetamino]-3-acetoacetoxymethyl-3-cephem-4-carboxylic acid (syn isomer): mp 101 to 1060C (dec.). IR (Nujol) : 3400, 3300, 3170, -1770, 1710, 1660, 1620, 1525, 1145, 1035 cm Physical constants of sodium 7-[2-etEoxyimino-2- (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-aceto- acetoxymethyl-3-cephem-4-carboxylate (syn isomer): mp 175 to 1800C (dec.). IR (Nujol) : 3450, 3300, 3100, 1790, 1720, 1670, 1640, 1610, 1550 cm NMR (D20, 6) : 1.38 (3H, t, J=6Hz), 2.34 (3H, s), 3.44, 3.66 (2H, ABq, J-18Hz), 4.40 (2H, q, J=6Hz), 5.05, 5.86 (2H, ABqo J=12Hz), 5.26 (1H, d, J=4Hz), 5,90 (1H, d, J=4Hz) Preparatin 11 The following compounds were obtained according to a similar manner to that of Preparation 10. (1) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamino]-3-acetoacxetoxymethyl 3-cephem-4-carboxylic acid (syn isomer), powder, mp. 130 to 1350C (dec.). IR (Nujol) : 3300, 1780, 1720, 1680, 1620, 1525 cm 1 NMR (DMSO-d6, 6) : 1.3-2.0 (8H, m), 2.15 (3H, s), 3.52 (2H, bs), 3.60 (2H, s), 4.5-4.7 (1H, m), 4.77, 5.00 (2H, ABq, J=14Hz), 5.13 (1H, d, J=4Hz), 5.80 (1H, 2d, J=4 and 8Hz), 8.10 (2H, s), 9.50 (1H, d, J=8Hz) (2) 7-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-acetoacetoxy methyl-3-cephem-4-carboxylic acid (syn isomer), mp. 135 to 1400C (dec.). IR (Nujol) : 3400, 3300, 3200, 1775, 1735, 1710, 1675, 1620, 1525 cm NMR (DMSO-d6, d) : 1.93-2.47 (4H, m), 2.18 (3H, s), 3.55 (2H, bs), 3.65 (2H, s), 4.80, 5.07 (2H, ABq, J=13Hz), 5.13 (1H, d, J=5Hz), 5.23-5.53 (1H, m), 5.70-6.23 (3H, m), 8.12 (2H, bs), 9.50 (lH, d, J=8Hz) (3) 7-[2-Carboxymethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-acetoacetoxymethyl 3-cephem-4-carboxylic acid (syn isomer), mp. 95 to 1000C (dec.). IR (Nujol) : 3400, 3290, 3190, 1770, 1720, 1615, 1520 cm 1 NMR CDMSO-d6, 6) : 2.17 (3H, s), 3.53 (2H, bs), 3.63 (2H, s), 4.67 (2H, s), 4.80, 5.07 (2H, ABq, J=13Hz), 5.15 (1H, d, J=5Hz), 5.87 (IH, 2d, J=5 and 8Hz) 8.15 (2H, bs), 9.53 (IH, d, J=8Hz) (4) 7-[2-t-Butoxycarbonylmethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-acetoacetoxy- methyl-3-cephem-4-carboxylic acid (syn isomer), mp. 105 to 1100C (dec.). IR (Nujol) : 3350, 3250, 1780, 1720, 1620, 1525 cm NMR (DMSO-d6, d) : 1.43 (9H, s), 2.17 (3H, s), 3.53 (2H, bs), 3.63 (2H, s), 4.63 (2H, s), 4.82, 5.05 (2H, ABq, J=13Hz), 5.15 (lH, d, J=SHz), 5.85 (1H, 2d, J=5 and 8Hz), 8.15 (2H, bs), 9.53 (1H, d, J=8Hz) (5) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]cephalosporanic acid (syn isomer). mp 140 to 1450C (dec.). IR (Nujol) : 3480, 3370, 3250, 1785, 1730, 1680, 1630, 1530 cm NMR (DMSO-d6, 6) : 1.33-2.17 (8H, m), 2.03 (3H, s), 3.57 C2H, broad s), 4.60-4.90 C1H, m), 4.73 and 4.97 (2H, ABq, J=13Hz), 5.15 (1H, d, J=5Hz), 5.80 (1H, dd, J=5 and 8Hz), 8.10 (2H, broad s), 9.47 (1H, d, J=8Hz) (6) 7-[2-(2-Cyclopenten-1-yl)oxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]cephalosporanic acid (syn isomer). mp 154 to 1590C (dec.). IR (Nujol) : 3300, 1770, 1720, 1670, 1620, 1520 cm1 NMR (DMSO-d6, d) : 2.0 (3H, s), 2.0-2.40 (4H, m), 3.52 (2H, broad s), 4.70 and 4.97 (2H, ABq, J=14Hz), 5.12 (1H, d, J=4Hz), 5.27-5.40 (1H, m), 5.82 (1H, dd, J=4 and 8Hz), 5.83-6.17 (2H, m), 8.13 (2H, s), 9.50 (1H, d, J=8Hz) (7) 7- [2- (t-Butoxycarbonylmethoxyimino) -2- (5-amino 1,2,4-thiadiazol-3-yl)acetamido]cephalosporanic acid (syn isomer), mp 125 to 130 C (dec.). IR (Nujol) : 3300, 3200, 1770, 1720, 1680, 1620, 1520 cm-Ú NMR (DMSO-d6, 6) : 1.50 (9H, s), 2.10 (3H, s), 3.62 (2H, broad s), 4.68 (2H, s), 4.77 and 5.03 (2H, ABq, J=13Hz), 5.20 (lH, d, J=4Hz), 5.88 (1H, dd, J=4 and 8Hz), 8.18 (2H, s), 9.55 (lH, d, J=8Hz) (8) 7-[2-Carboxymethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]cephalosporanic acid (syn isomer), mp 160 to 165 C (dec.). IR (Nujol) : 3300, 3200, 1770, 1720, 1680, 1520 cm-Ú NMR (DMSO-d2, d) : 2.10 (3H, s), 3.60 (2H, broad s), 4.70 (2H, s), 4.77 and 5.03 (2H, ABq, J=14Hz), 5.20 (1H, d, J=4Hz), 5.88 (1H, dd, J=4 and 8Hz), 8.18 (2H, s), 9.57 (1H, d, J=8Hz) Preparation 12 To a suspension of 7-C2-thienyl)acetamido-3- (3-hydroxymethyl-1-pyridiniomethyl)-3-cephem-4carboxylate (27.0 g) and N,N-dimethylaniline (50.8 g) in methylene chloride (240 ml) was dropped trimethylsilyl chloride (26.0 g) under stirring and the mixture was stirred for 1.5 hours at room temperature. To the resulting solution was added phosphorous pentachloride (31.2 g) at -300C and the mixture was stirred for one hour at -30 C to -250C. The mixture was added to a solution of n-butanol (120 g) in methylene chloride (240 ml) at -250C under stirring, and the stirring was continued for 1.5 hours at room temperature. A resulting precipitate was collected by filtration, washed with methylene chloride and dried on phosphorous pentoxide to give 7-amino-3-(3-hydroxymethyl-1- pyridiniomethyl)-3-cephem-4-carboxylate dihydrochloride (25.5 g), mp 120 to 1250C (dec.). -1 IR (Nujol) : 1780, 1700, 1630 cm NMR (DCl+D2O, d): 3.60, 3.83 (2H, ABq, J=l8Hz), 4.97 (2H, s), 5.33 (lH, d-, J=5Hz), 5.47 (1H, d, J=5Hz), 5.60, 5.93 (2H, ABq, J=14Hz), 8.0-8.33 (1H, m), 8.50-8.76 (1H, m), 8.83-9.16 (2H, m) EMI35.1 To a mixture of 3-hydroxymethylpyridine (26.6 g) and sodium iodide (150 g) in formamide (240 ml) was added sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-cephalosporanate (syn isomer) (60 g) by portions at 750C under stirring, which was continued for 3 hrs. at 80 to 850C. The mixture was cooled to 200C and diluted with isopropyl alcohol (3 Q) to give an oily substance, which was separated by decantation. The separated oily substance was triturated in isopropyl alcohol (1 Q) to give a crude object compound as a powder. The crude product was dissolved in water (500 ml) and subjected to column chromatography on a non ionic adsorption resin "Diaion HP-20"(Trademark, prepared by Mitsubishi Chemical Industries) (1.8 t). After the Column was washed with water C5.5 #), the elution was carried out with 30 % aqueous methanol. The eluates (2.5 Q) containing an object compound were collected, concentrated to 550 ml under reduced pressure and passed through a column packed with acidic alumina (150 g). The eluate (700 ml) was lyophilized to give white powder of 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-hydroxymethyl-1-pyridiniomethyl)-3-cephem- 4-carboxylate (syn isomer) (12,5 g), mp 160 to 1650C(dec.). I.R. (Nujol) : 3300, 1770, 1660, 1610, 1520 cm 1 N.M.R. (D2O,#) : 1.23 (3H, t, J=7Hz), 3.23 and 3.57 (2H, ABq, J=17Hz), 4.30 (2H, q, J=7Hz), 4.83 (2H, s), 5.23 (1H, d, J=4Hz), 5.33 and 5.53 (2H, ABq, J=14Hz), 5.85 (1H, d, J=4Hz), 8.03 (1H, dd, J=6 and 8Hz), 8.50 (1H, d, 3=8Hz), 8,85 (1H, d, J=6Hz), 8.90 (1H, s) Example 2 EMI36.1 To a mixture of 4-(2-sulfoethyl)pyridine (4*56 g), potassium thiocyanate (24 g) and sodium carbonate (1.3 g) in water (25 ml) was added sodium 7-[2- ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]cephalosporanate (syn isomer)(6.0 g) at 500C under stirring. The mixture was stirred for 4.5 hours at 60 to 650C, diluted with cold water and adjusted to pH 3 with 1N-hydrochloric acid. The solution was washed with ethyl acetate, evaporated to remove ethyl acetate and subjected to column chromatography on a non ionic adsorption resin "Diaion HP-20" (Trademark: Prepared by Mitsubishi Chemical Industries) (450 ml). After the column was washed with water, the elution was carried out with 20% aqueous methanol. The eluates containing an object compound were col- lected, evaporated to remove methanol under reduced pressure and lyophilized to give sodium 7-[2ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-t4-(2-sulfonatoethyl)-1-pyridiniomethyl]- 3-cephem-4-carboxylate (syn isomer) (2.3 g), mp 165 to 171 C (dec.). I.R. (Nujol) : 3500-3200, 1765, 1660, 1630, 1610, 1520 cm 1 N.M.R. (D2O, #) : 1.32 (3H, t, J=7Hz), 3.16 and 3.69 (2H, ABq, J=liHz), 3.37 (4H, s), 4.34 (2H, q, J=7Hz), 5.27 (1H, d, J=5Hz), 5.28 and 5.57 (2H, ABq, J=13Hz), 5.84 (1H, d, J=5Hz), 7.97 (2H, d, J=7Hz), 8.81 (2H, d, J=7Hz) Example 3 To a mixture of 3-hydroxypyridine (2.32 g) and sodium iodide (15 g) in formamide (15 ml) was added sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]cephalosporanate (syn isomer) (6.0 g) at 750C under stirring, which was continued for 2.5 hours at 80 to 820C. The mixture was cooled to room temperature and poured into isopropyl alcohol (150 ml). The resulting precipitates were collected by filtration, washed with isopropyl alcohol and diisopropyl ether and then dissolved in water (80 ml). The aqueous solution was adjusted to pH 3 with 6N-hydrochloric acid, washed with ethyl acetate, evaporated to remove ethyl acetate and subjected to column chromatography on a non ionic adsorption resin "Diaion HP-2û" (160 ml). After the column was washed with water, the elution was carried out with 30% aqueous methanol. The eluates containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido] 3- (3-hydroxy-1-pyridiniomethyl) -3-cephem-4-carboxylate (syn isomer) (0.93 g), mp 175 to 1800C (dec.). IR (Nujol) : 3390, 3290, 3180, 3050, 1770, 1660, 1625, 1610, 1525 cm1 NMR (DMSO-d6+D2O, 6) : 1.20 (3H, t, J=7Hz), 3.17 and 3.47 (2H, ABq, J=18Hz), 4.13 (2H, q, J=7Hz), 5.07 (1H, d, J=SHz), 5.22 and .5.52 (2H, ABq, J=14Hz), 5.70 (lH, d, J=5Hz), 7.67-8.17 (2H, m), 8.40-8.90 (2H, m) Example 4 EMI38.1 A mixture of 3-hydroxymethylpyridine (1.3 g) and potassium iodide (7.95 g) in water (5.3 ml) was warmed to 600C under stirring and sodium 7-[2-cyclopentyloxyimino-2 (S-amino-1,2,4-thiadiazol-3-yl)acetamido]cephalosporanate (syn isomer)(5.32 g) was added thereto. The mixture was stirred for 5 hours at 60aC and diluted with a mixture of water (100 ml), ethyl acetate (50 ml) and acetone (10 ml). The mixture was adjusted to pH 1 with 6N hydrochloric acid and the aqueous layer was separated out. The aqueous solution was evaporated to remove acetone and ethyl acetate and subjected to column chromatography on a non ionic adsorption resin "Diaion HP-20" (160 ml). After the column was washed with water (500 ml), the elution was carried out with 40% aqueous methanol. The eluates containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2-cyclopentyloxyimino-2- (S-amino-1,2,4-thiadiazol-3-ylZacetamido3-3-(3- hydroxymethyl-l-pyridiniomethyl).- 3-cephem-4-carboxylate (syn isomer)(1.2 g), white powder, mp 160 to 1650C (dec.). IR (Nujol) : 3260, 3170, 1770, 1655, 161O, 1520 cm 1 NMR (DMSO-d6, @) : 1.33-2.00 (8H, m), 3.17, 3.50 (2H, ABq, J=18Hz), 4.57-4.90 ±3H, m), 5,08 (1H, d, J=5Hz), 5.30, 5.65 ±2H, ABq, J-14Hz), 5.70 (lH, 2d, J=5 and 8Hz), 8.00-8.33 (3H, m), 8.33-8.67 t1H, m), 9.17-9.43 (2H, m), 9.42 (1H, d, J=8Hz) Example 5 To a mixture of thiazole (2.5 ml), sodium iodide (18.0 g) and water 3 ml was added sodium 7-[2ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl]acetamido]cephalosporanate (syn isomer)(5.41 g) at 600C under stirring, which was continued for one hour at 75 C. The reaction mixture was diluted with water (50 ml), adjusted to pH 3.6 with 1N hydrochloric acid and filtered. The filtrate was subjected to column chromatography on a non ionic adsorption resin 1,Diaion HP-20" (150 ml). After the column was washed with water, the elution was carried out with 20% aqueous methanol. The eluants containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3- (3-thiazoliomethyl)-3-cephem-4-carboxylate (syn isomer) (2.3 g), mp 155 to 1600C (dec.). IR (Nujol): 3400-3200, 1770, 1660, 1600, 1520 cm NMR (D2O, ô) : 1.30 (3H, t, J=7Hz), 3.2t? and 3.72 (2H, ABq, J=18Hz), 4.32 (2H, q, J=7Hz), 5.25 (1H, d, J=5Hz), 5.29 and 5.50 (2H, ABq, J=13Hz), 5.83 (1H, d, J=5Hz), 8.19 (1H, d, J=4Hz), 8.42 (1H, d, J=4Hz) Example 6 A mixture of sodium iodide (13 g), dodecyl isonicotinate (5.8 g), 7-[2-ethoxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamido]-3-acetoacetoxymethyl-3-cephem4-carboxylic acid (syn isomer)(5.12 g), water (2.6 ml) and acetonitrile (7.8 ml) was stirred at 500 to 600C for 2 hours. To the reaction mixture was added a mixture of ethyl acetate (60 ml) and water (60 ml). A resulting precipitate was filtered and dissolved in a mixed solvent (1:1) of chloroform and ethanol. The solution was washed with water, dried over magnesium sulfate and concentrated to 30 ml. The resulting precipitates were filtered, washed with ethyl acetate and dried to give 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido)-3- (4-dodecyloxycarbonyl-1-pyridiniomethyl) -3- cephem-4-carboxylate (syn isomer) (2.2 g), mp 152 to 1570C (dec.). IR (Nujol) : 3280, 3160, 1775, 1730, 1675, 1610, 1520 cm-Ú NMR (DMSO-d6+D2O, 6) : 0.86 (3H, t, Jg6Hz), 1.0-1.9 (23H, m), 3.22 and 3.58 (2H, ABq, J=18Hz), 3.9-4.5 (4H, m), 5.12 (1H, d, J=5Hz), 5.10 and 5.76 (2H, ABq, J-14Hz), 5.72 (1H, d, J=SHz), 8.52 (2H, d, J=6Hz), 9.56 (2H, d, J=6Hz) Example 7 The following compound was obtained by reacting sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol3-yl)acetamido]3-acetoacetoxymethyl-3-cephem-4carboxylate (syn isomer) with 4-cyanopyridine according to similar manners to those of Examples 1 to 6. 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-[4-cyano-1-pyridiniomethyl)-3-cephem 4-carboxylate (syn isomer), mp 147 to 1510C (dec.). 1R (Nujol) : 3400-3100, 1780, 1670, 1610, 1530, 1040 cm-Ú NMR (D2O, #) : 1.31 (3H, t, J=7Hz), 3.20 and 3.70 (2H, ABq, J-18Hz), 4.31 (2H, q, J=7Hz), 5,25 (1H, d, J=5Hz), 5.40 and 5.71 (2H, ABq, J=14Hz), 5.82 (1H, d, J=5Hz), 8.45 (2H, d, J=6Hz), 9.26 (2H, d, J=6Hz) Example 8 The following compounds were obtained according to similar manners to those of Examples 1 to 7. (1) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]3-(4-hydroxymethyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 150 to 1550C (dec.). IR (Nujol) : 3250, 1770, 1660, 1630, 1605, 1570, 1520 cm 1 NMR (DMSO-d6+D2O,#) : 1.23 (3H, t, J=7Hz), 3.22 and 3.58 (2H, ABq, J=18Hz), 4.25 (2H, q, J=7Hz), 4.90 (2H, s), 5.17 (lH, d, J=5Hz), 5.28 and 5.65 (2H, ABq, J=14Hz), 5.80 (1H, d, J=SHz), 8.12 (2H, d, J=6Hz), 9.28 (2H, d, J=6Hz) (2) 7-[2-Ethoxyimino-2-(5-aminool,2,4-thiadiazol-3- yl)acetamido]3-(4-carboxy-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 175 to 185 C (dec.). IR (Nujol) : 3400-3150, 1780, 1670, 1630, 1560, 1530, 1040 cm NMR (D2O, #) : 1.22 (3H, t, J=7Hz), 3.23 and 3.63 (2H, A3q, J=l8Hz), 4.13 (2H, q, J=7Hz), 5.12 (1H, d, J=5Hz), 5.33 and 5.65 ±2H, ABq, j=14Hz), 5,80 (1H, d, J=5Hz), 8.28 (2H, d, J=6Hz), 9.13 (2H, d, J=6Hz) (3) 7- [2-Ethoxyimino-2- (5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-[4-(3-hydroxypropyl)-1-pyridinio methyl) -3-cephem-4-carboxylate (syn isomer), mp 159 to 167 c (dec.) IR (Nujol) : 3400-3100, 1770, 1670-1610, 1540 cm 1 NMR (DMSO-d6+D2O, 6) : 1.23 (3H,t, J=7Hz), 1.7-2.1 (2H, m), 2.8-3.3 (2H, m), 3.2-4.0 (4H, m), 4.20 (2H, q, J=7Hz), 5.05 (1H, J=SHz), 5.13 and 5.63 (2H, ABq, J=l4Hz), 5.75 (1H, d, J=5Hz), 8.02 (2H, d, J=7Hz), 9.17 (2H, d, J=7Hz) (4) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3-chloro-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 210 to 2200C (dec.). -1 IR (Nujol) : 3400-3100, 1770, 1660, 1610, 1520 cm NMR (DMSO-d6+D20, d) : 1.23 (3H, t, J=7Hz), 3.17 and 3.50 (2H, ABq, J=18Hz), 4.15 (2H, q, J-7Hz), 5.08 (IH, d, J=5Hz), 5.0-5.8 (2H, m), 5.73 (1H, d, J=5Hz), 7.8-8.8 (2H, m), 9.4 (1H, m), 9.7 (1H, m) (5) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiszol-3 yl)acetamido]-3-(3-methyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 175 to 1800C (dec.). IR (Nujol) : 3280, 1770, 1660, 1610, 1530, 1035 cm-Ú NMR CD2O, d) : 1.26 (3H, t, J=7Hz), 2.50 (3H, s), 3.12 and 3.75 (2H, ABq, J=18Hz), 4.29 (2H, q, J=7Hz), 5.22 (1H, d, J=5Hz), 5.20 and 5.53 (2H, ABq, J=13Hz), 5.82 (1H, d, J=5Hz), 7.88 (1H, m), 8.35 (1H, m), 8.73 (2H, m) (6) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3,5-dimethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 165 to 175 C (dec.). IR (Nujol) : 3400-3150, 1770, 1660, 1610, 1530 cm NMR (D2O, d) : 1.32 (3H, t, J=7Hz), 2.50 (6H, s), 3.21 and 3.62 (2H, ABq, J=18Hz), 4.32 (2H, q, J=7Hz), 4.87 (1H, d, J=5Hz), 5.0-5.6 (3H, m), 8.16 (1H, bs), 8.58 (2H, s) (7) 7-[2-Ethoxyimino-2-(5-amino^1,2,4-thiadiazol-3- yl)acetamido]-3-(4-butoxycarbonylaminomethyl-1 pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), mp 154 to 1580C Cdec.). IR (Nujol) : 3600, 1775, 1670, 1640, 1610, 1520, 1280, 1035 cm-Ú MNR (D2O, #) : 1.21 (3H, t, J=7Hz), 1.40 (9H, s), 3.0-3.7 (2H, m), 4.13 (2H, q, J=7Hz), 4.40 (2H, broad s), 5.03 (1H, d, J=5Hz), 4.9-5.8 (2H, m), 5.67 (1H, d, J=5Hz), 7.90 (2H, d, J=6Hz), 9.25 (2H, d, J=6Hz) (8) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-aminomethyl-1-pyridiniomethyl)¯ 3-cephem-4-carboxylate diformate (syn isomer), mp 149 to 159 C (dec.). IR (Nujol) :- 3250, 3150, 1770, 1660, 1646, 1580, 1520, 1040 cm-1 (9) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-t-butyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 169.5 to 175.00C (dec.). IR (Nujol) : 3280, 1770, 1670, 1630, 1610, 1530 cm-1 NMR (D2O, d) : 1.40 (9H, s), 1.88 (3H, t, J=7Hz), 3.13 and 3.70 (2H, ABq, J=19Hz), 4.21 (2H, q, J=7Hz), 5.25 and 5.56 (2H, ABq, J=14Hz), 5.28 (111, d, J=5Hz), 5.87 (1H, d, J=5Hz), 8.05 (2H, d, J=7Hz), 8.82 (2H, d, J=7Hz) (10) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3350, 3200, 1775, 1670, 1615, 1525 cm 1 NMR (DMSO-d6, d) : 1.20-2.00 (8H, m), 3.13, 3.50 (2H, ABq, J=18Hz), 4.57- 4.98 (3H, m), 5,08 (1H, d, J=5Hz), 5.25, 5.60 (2H, ABq, J=14Hz), 5.67 (1H, 2d, J=S and 8Hz), 8.05 (2H, d, J=6Hz), 8.10 (2H, bs), 9.27 (2H, d, J=6Hz), 9.40 (1H, d, J=8Hz) (11) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thïadiazol-3-yl)acetamido]-3-(4-acetyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 145 to 1500C (dec.). IR (Nujol) : 3270, 1770, 1700, 1670, 1610, 1520 cm 1 NMR (DMSO-d6+D2O, #) : 1.33-2.00 (8H, m), 2.67 (3H, s), 3.07, 3.45 (2H, ABq, J=18Hz), 4.50-4.77 (1H, m), 5.02 (1H, d, J=5Hz), 5.25, 5.58 (2H, ABq, J=14Hz), 5.63 (1H, d, J=5Hz), 8.40 (2H, d, J=6Hz), 9.52 (2H, d, J=6Hz) (12) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-carboxymethyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 165 to 170 C (dec.) IR (Nujol) : 3350, 3200, 1775, 1720, 1670, 1620, 1525 cm NMR (DMSO-d6+D2O, #) : 1.30-2.00 (8H, m), 3.17, 3.52 (2H, ABq, J=18Hz), 3.93 (2H, s), 4.57-4.87 (1H, m), 5.07 (1H, d, J=5Hz), 5.27, 5.63 (2H, ABq, J=14Hz), 5.70 (1H, d, J=5Hz), 7.93-8.23 (1H, m), 8.37-8.63 (1H, m), 9.10-9.37 (2H, m) (13) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-hydroxyiminomethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate(syn isomer), mp 140 to 145 C (dec.). IR (Nujol) : 3280, 3160, 1770, 1680, 1630, 1610, 1520 cm-1 NMR (DMSO-d6, #) : 1.33-2.00 (8H, m), 3.23, 3.57 (2H, ABq, J=18Hz), 4.57-4.90 (1H, m), 5.12 (1H, d, Js5Hz), 5.28, 5.65 (2H, ABq, J=14Hz), 5.73 (1H, 2d, J=5 and 8Hz), 8.18 (2H, bs), 8.25 (2H, d, J=6Hz), 8.42 (1H, s), 9.35 (2H, d, J=6Hz), 9.43 (1H, d, J=8Hz) (14) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-[4-methyl-5-(2 hydroxyethyl)-3-thiazoliomethyl]-3-cephem-4 carboxylate (syn isomer), mp 150 to 155 C (dec.). IR (Nujol) : 3330, 1780, 1670, 1610, 1530 cm 1 NMR (DMSO-d6, #) : 1.33-2.00 (8H, m), 2.57 (3H, s), 2.90-3.17 (2H, m), 3.17-3.43 (2H, m), 3.57-3.80 (2H, m), 4.60-4.90 (1H, m), 5.07 (1H, d, J=5Hz), 5.37 (2H,bs), 5.70 (1H, 2d, J=5 and 8Hz), 8.17 (2H, bs), 9.43 (1H, d, J=8Hz), 10.23 (1H, s) (15) 7-[2-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 140 to 1450C (dec.). IR (Nujol) : 3300, 3200, 1770, 1660, 1620, 1520 cm 1 NMR (DMSO-d6, 6) : 1.8-2.5 (4H, m), 3.13, 3.50 (2H, ABq, J=18Hz), 4.83 (2H, s), 5.07 (1H, d, J=4Hz), 5.20-5.40 (1H, m), 5.27, 5.67 (2H, ABq, J=14Hz), 5.80 (1H, 2d, J=4 and 8Hz), 5.87-6.20 (2H, m), 8.07 (2H, d, J=7Hz), 8.17 (2H, s), 9.33 (2H, d, J=7Hz), 9.47 (1H, d, J=8Hz) (16) 7-[2-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 143 to 148 C. Cdec.). IR (Nujol) : 3300, 3200, 1770, 1660, 1610, 1520 cm 1 NMR (DMSO-d6, #) : 1.8-2.5 (4H, m), 3.13, 3.47 (2H, ABq, J=17Hz), 4.73 (2H, s), 5.35 (1H, d, J=4Hz), 5.17-5.40 (1H, m), 5.40-6.20 (5H, m), 8.13 (2H, s), 8.0-8.30 (1H, m), 8.37-8.60 (1H, m), 9.27-9.43 (2H, m), 9.47 (1H, d, J=8Hz) (17) 7-[2-Carboxymethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 170 to 1750C (dec.). IR (Nujol) : 3300, 1770, 1670, 1620, 1525 cm 1 NMR (DMSO-d6+D2O, 8) : 3.20, 3.50 (2H, ABq, J=18Hz), 4.63 (2H, s), 4.73 (2H, s), 5.07 (1H, d, J=4Hz), 5.27, 5.60 (2H, ABq, J=14Hz), 5.87 (111, d, J=4Hz), 7.90-8.17 (1H, m), 8.37-8.60 (1H, m), 9.0-9.3 (2H, m) (18) 7-[2-Ethoxycarbonylmethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 155 to 1600C (dec.). -1 IR (Nujol) : 3400-3150, 1770, 1670, 1610 cm NMR (DMSO-d6+D20, d) : 1.23 (3H, t, J=7Hz), 3.11, 3.67 (2H, ABq, J=18Hz), 4.23 (2H, q, J=7Hz), 4.82 (4H, bs), 5.17 (1H, d, J=5Hz), 5.30, 5.73 (2H, ABq, J=13Hz), 5,83 (1H, d, J=5Hz), 8.17 (1H, m), 8.60 (1H, m), 9.23 (2H, m) (19) 7-[2-t-Butoxycarbonylmethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3- (3-hydroxymethyl- 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 145 to 1500C (dec.). IR (Nujol) : 3300, 1775, 1740, 1670, 1610, 1525 cm 1 NMR (DMSO-d6+D2O, #) : 1.50 (9H, s), 3.23, 3.60 (2H, ABq, J-17Hz), 4.65 (2H, s), 4.80 (2H, s), 5.13 (1H, d, J=4Hz), 5.37, 5.67 (2H, ABq, J=l4Hz), 5.80 (1H, d, J=4Hz), 8.23 (2H, s), 8.0-8.27 (1H, m), 8.43-8.67 (111, m), 9.30-9.50 (2H, m), (20) 7-[2-(1-Methyl-1-ethoxycarbonylethoxyimino)-2 (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3 (3-hydroxymethyl-1-pyridiniomethyl)-3-cephem-4 carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3400-3200, 1780, 1740, 1680 cm 1 NMR (DMSO-d6+12O, #) : 1.16 (3H, t, J=7Hz), 1.48 (6H, s), 3.16, 3.62 (2H, ABq, J=18Hz), 4.16 (2H, q, J=7Hz), 4.80 (2H, s), 5.14 (1H, d, J=5Hz), 5.2-5.8 (2H, m), 5.80 (111, d, J=5Hz), 8.20 (1H, m), 8.56 (1H, m), 9.32 (2H, m) (21) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3Zyl)- acetamido]-3-[4-(N-hydroxycarbamoyl)-1-pyridinio methyl]-3-cephem-4-carboxylate (syn isomer), mp 178 to 1850C (dec.). IR (Nujol) : 3250, 3180, 1770, 1670, 1640, 1605, 1530 cm 1 NMR (D2O, #) : 1.29 (3H, t, J=7Hz), 3.20 and 3.72 (2H, ABq, J=19Hz), 4.30 (2H, q, J=7Hz), 5.28 (1H, d, J=5Hz), 5.37 and 5.70 (2H, ABq, J=14Hz), 5.88 (1H, d, J=5Hz), 8.31 (2H, d, Js7Hz), 9.13 (2H, d, J=7Hz) (22) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-butoxycarbonyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 154 to 1590C (dec.). IR (Nujol) : 3300, 3160, 1775, 1728, 1670, 1605, 1525 cm-1 NMR (DMSO-d6+D2O, #) : 0.8-2.0 (10H, m), 3.13 and 3.53 (2H, ABq, J=18Hz), 4.0-4.6 (4H, m), 5.08 (1H, d, J=5Hz), 5.33 and 5.76 (2H, ABq, J=14Hz), 5.73 (1H, d, J=5Hz), 8.55 (2H, d, J=6Hz), 9.72 (2H, d, J=611z) (23) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-t-butoxycarbonyl-1 pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), mp 154 to 1570C (dec.). IR (Nujol) : 3300, 3150, 1775, 1725, 1670, 1610, 1525 cm-1 NMR (DMSO-d6+D2O, #) : 1.23 (3H, t, J=6.5Hz), 1.60 (9H, s), 3.25 and 3.63 (2H, ABq, J=18Hz), 4.17 (2H, q, J=6.5Hz), 5.10 (1H, d, J=5Hz), 5.30 and 5.83 (2H, ABq, J=14Hz), 5.72 (1H, d, J=5Hz), 8.52 (2H, d, J=6Hz), 9.68 (2H, d, J=6Hz) (24) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-[4-(N-butylcarbamoyl)-1-pyridiniomethyl] 3-cephem-4-carboxylate Csyn isomer), mp 161 to 162 C (dec.). IR (Nujol) : 3270, 1775, 1655, 1610, 1560, 1530 cm NMR (DMSO-d6, #) : 0.90 (3H, t, J=7Hz), 1.20 (3H, t, J=7Hz), 1.1-1.8 (4H, m), 2.9-3.9 (4H, m), 4.15 (2H, q, J=7Hz), 5.08 (1H, d, J=5Hz), 5.28 and 5.73 (2H, ABq, J=14Hz), 5.72 (1H, 2d, J=5 and 8Hz), 8.15 (2H, bs), 8.53 (2H, d, J=6Hz), 9.48 (1H, d, J=8Hz), 9.60 (2H, d, J=6Hz) (25) 7- [2-Ethoxyimino-2- (5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(N-t-butylcarbamoyl)-1-pyridinio methyl]-3-cephem-4-carboxylate (syn isomer), mp 165 to 1670C (dec.). IR (Nujol) : 3270, 1775, 1660, 1610, 1530 cm-Ú NMR (DMSO-d6+D2O, #) : 1.22 (3H, t, J=7Hz), 1.42 (9H, s), 3.16 and 3.50 (2H, ABq, J=18Hz), 4.17 (2H, q, J=7Hz), 5.08 (1H, d, J=5Hz), 5.25 and 5.68 (2H, ABq, J=14Hz), 5.72 (111, d, J=SHz), 8.47 (2H, d, J=7Hz), 9.62 (2H, d, J=7Hz) (26) 7[[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]3-[4-dodecylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 176 to 1770C (dec.). IR (Nujol) : 3270, 1770, 1655, 1610, 1540 cm-Ú NMR (DMSO-d6+D2O, #) : 0.85 (3H, t, J=5Hz), 1.0-1.8 (23H, m), 3.18 and 3.57 (2H, ABq, J=18Hz), 3.1-3.9 (2H, m), 4.15 (2H, q, J=7Hz), 5.0-6.0 (4H, m), 8.6 (2H, bs), 9.6 (2H, bs) (27) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-octyloxycarbonyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 155 to 1580C (dec.). IR (Nujol) : 3270, 1775, 1735, 1680, 1615, 1520 cm 1 NMR (DMSO-d6+D2O, d) : 0.86 (3H, t, J=6Hz), 1.0-1.7 (15H, m), 3.25 and 3.53 (2H, ABq, J=18Hz), 3.9-4.7 (4H, m), 5.15 (1H, d, J=SH2), 5.50 and 5.72 (2H, ABq, J=14Hz), 5.83 (1H, d, J=5Hz), 8.57 (2H, d, J=6Hz), 9.62 (2H, d, J=6Hz) (28) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-[4-(N-octylcarbamoylD-l-pyridiniomethyla- 3-cephem-4-carboxylate (syn isomer), mp 181 to 1830C (dec.). IR (Nujol) : 3250, 1770, 1655, 1610, 1565, 1550, 1530 cm-Ú NMR (DMSO-d6+D2O, 6) : 0.86 (3H, t, J=6Hz), 0.9-1.7 (15H, m), 2.9-3.6 (4H, m), 4.15 (2H, q, J=6Hz), 5.15 (1H, d, J=SHz), 5.15 and 5.77 (2H, ABq, J=14Hz), 5.77 (1H, d, J=5Hz), 8.62 (2H, d, J=6Hz), 9.51 (2H, d, J=6Hz) (29) 7- [2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-mesylamino-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 170 to 175 C (dec.). IR (Nujol) : 3400, 1760, 1670, 1610, 1520, 1150 cm-1 NMR (DMSO-d6, 6) : 1.17 (3H, t, J=7Hz), 2.87 (3H, s3, 3.20 and 3.47 (2H, ABq, J=16Hz), 4.10 (2H, q, J=7Hz), 5.10 (1H, d, J=4Hz), 5.17 and 5.47 (2H, ABq, J=14Hz), 5.80 (1H, 2d, J=4 and 8Hz), 7.6-8.5 (4H, m), 9.47 (1H, d, J=8Hz) (30) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(4-ethoxycarbonyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 150 to 1550C (dec.). IR (Nujol) : 3320, 3160, 1775, 1730, 1670, 1610, 1530, 1290 cm-1 NMR (DMSO-d6+D2O, 6) : 1.21 (3H, t, J=7Hz), 1.36 (3H, t, J=7Hz), 3.12, 3.52 (2H, ABq, J=18Hz), 4.12 (2H, q, J=7Hz), 4.43 (2H, q, J=7Hz), 5.06 (1H, d, J=5Hz), 5.33, 5.68 (2H, ABq, J=14Hz), 5.71 (111, d, J=5Hz), 8.47 (2H, d, J=6Hz), 9.60 (2H, d, J=6Hz) Example 9 A solution of 7-[2-ethoxyimino-2-(5-amino-1,2,4thiadiazol-3-yl)acetamido]-3-(4-t-butoxycarbonylaminomethyl-1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer) C1.23 g) in formic acid (20 ml) was stirred for 6.5 hours at ambient temperature. The solution was evaporated to dryness under reduced pressure and the residue was dissolved in water. An insoluble material was filtered off and the filtrate was subjected to column chromatography on a non-ionic adsorption resin "Diaion HP-20" (50 ml). The elution was carried out with water. The'eluates containing an object compound were collected and lyophilized to give 7-[2-ethoxyimino 2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-C4- aminomethyl-1-pyridiniomethyl) -3-cephem-4-carboxylate diformate (syn isomer) (0.37 g), mp 149 to 1590C (dec.). IR (Nujol) : 3250, 3150, 1770, 1660, 1640, 1580, 1520, 1040 cm-Ú NMR (D2O, 6) : 1.22 (3H, t, J=7Hz), 3.3-3.9 (2H, m), 4.05 (211, broad s), 4.17 (211, q, J=7Hz), 4.9-5.6 (211, m), 5.06 (111, d, J=4Hz), 5.70 (1H, d, J=4Hz), 7.45 (2H, d, J=5Hz), 8.26 (211, s), 8.55 (211, d, J=511z) Example 10 To a cold solution of phosphorus pentachloride (3.2 g) in methylene chloride (45 ml) was added 2-t-butoxycarbonylmethoxyimino-2-(S-amino-1,2,4 thiadiazol-3-yl)acetic acid (syn isomer) (4.2 g) at -180C and the mixture was stirred for 45 minutes at -12 to -100C. To the reaction mixture was added diisopropyl ether (150 ml) at -100C and the mixture was stirred for several minutes and the resulting precipitate was collected by filtration. On the other hand, a mixture of 7-amino-3-(3-hydroxymethyl- 1-pyridiniomethyl)-3-cephem-4-carboxylate dihydroxhloride (4.0 g) and trimethylsilylacetamide (20 g) in methylene chloride (40 ml) was stirred for 30 minutes at room temperature and cooled to -200C. To the cold solution was added the precipitate obtained above and the mixture was stirred for 30 minutes at -10 to -5 C. The reaction mixture was poured into an aqueous solution (100 ml) of sodium bicarbonate (5.9 g) and stirred for 30 minutes at room temperature. The aqueous layer was separated out. To the aqueous solution was added ethyl acetate and the mixture was adjusted to pH 1.5 with 6N hydrochloric acid. The aqueous layer was separated out, washed with ethyl acetate and subjected to column chromatography on a non ionic adsorption resin "Diaion HP-20" (100 ml). After the column was washed with water. The elution was carried out with 40% aqueous methanol. The eluates containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2-t-butoxycarbonylmethoxyimino- 2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-(3hydroxymethyl-l-pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer) (2.2 g), mp 145 to 1500C (dec.). IR (Nujol) : 3300, 1775, 1740, 1670, 1610, 1525 cm 1 NMR (DMSO-d6+D2O, 6) : 1.50 (9H, s), 3.23, 3.60 (211, ABq, J=17Hz), 4.65 (2H, s), 4,80 (2H, s), 5.13 (111, d, J=4Hz), 5.37, 5.67 (211, ABq, J=14Hz), 5.80 (111, d, J=4Hz), 8.23 (211, s), 8.0-8.27 (1H, m), 8.43-8.67 (1H, m), 9.30-9.50 (211, m). Example 11 The following compounds were obtained according to a similar manner to that of Example 10. (1) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-hydroxymethyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 160 to 1650C (dec.). IR (Nujol) : 3300, 1770, 1660, 1610, 1520 cm 1 (2) Sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido)-3- L4- (2-sulfonatoethyl)- 1-pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 165 to 1710C (dec.). IR CNujol) : 3500-3200, 1765, 1660, 1630, 1610, 1520 cm 1 (3) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-hydroxy-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 175 to 1800C (dec.). IR (Nujol) : 3390, 3290, 3180, 3050, 1770, 1660, 1625, 1610, 1525 cm (4) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3- (4-cyano-1-pyridiniomethyl) -3 cephem-4-carboxylate (syn isomer), mp 147 to 1510C (dec.). IR (Nujol) : 3400-3100, 1780, 1670, 1610, 1530, 1040 cm (5) 7-E2-Ethoxyimino-2-(5-amino-1,2,4-tSiadiazol-3-ylD- acetamido]-3-(4-hydroxymethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 150 to 1550C (dec.). IR (Nujol) : 3250, 1770, 1660, 1630, 1605, 1570, 1520 cm1 (6) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-carboxy-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 175 to 1850C (dec.). IR (Nujol) : 3400-3150, 1780, 1670, 1630, 1560, 1530, 1040 cm 1 (7) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-[4-C3-hydroxypropyl)-1-pyridinio methyl]-3-cephem-4-carboxylate (syn isomer), mp 159 to 1670C (dec.). IR (Nujol) : 3400-3100, 1770, 1670-1610, 1540 cm (8) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol]-3 yl)acetamido]-3-(3-chloro-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 210 to 22000 (dec.). IR (Nujol) : 3400-3100, 1770, 1660, 1610, 1520 cm-Ú (9) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3-methyl-1-pyridiniomethyl)-3 cephem-4-carhoxylate (syn isomer), mp 175 to 1800C (dec.). IR (Nujol) : 3280, 1770, 1660, 1610, 1530, 1035 cm 1 (10) 7-[2-Ethoxyimino-2-(5-amino-1 ,2,4 -thiadiazol-3- yl)acetamido]-3-(3,5-dimethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 165 to 1750C (dec.). IR (Nujol) : 3400-3150, 1770, 1660, 1610, 1530 cm 1 (11) 7-[2XEthoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-(4-t-butoxycarbonylaminomethyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 154 to 1580C (dec.). IR (Nujol) : 3600, 1775, 1670, 1640, 1610, 1520, 1280, 1035 cm-1 (12) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-aminomethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate diformate (syn isomer), mp 149 to 159 C (dec.). IR (Nujol) : 3250, 3150, 1770, 1660, 1640, 1580, 1520, 1040 cm (13) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-t-butyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp 169.5 to 175.00C (dec.). IR (Nujol) : 3280, 1770, 1670, 1630, 1610, 1530 cm (14) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3350, 3200, 1775, 1670, 1615, 1525 cm 1 (15) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 160 tQ 165 C (dec.). IR (Nujol) : 3260, 3170, 1770, 1655, 1610, 1520 cm (16) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-acetyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 145 to 1500C (dec.). IR (Nujol) : 3270, 1770, 1700, 1670, 1610,1520 cm 1 (17) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-carboxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 165 to 1700C (dec.). IR (Nujol) : 3350, 3200, 1775, 1720, 1670, 1620, 1525 cm (18) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-carboxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), nip 140 to 1450C (dec.). IR (Nujol) : 3280, 3160, 1770, 1680, 1630, 1610, 1520 cm (19) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2, thiadiazol-3-yl)acetamido]-3-[4-methyl-5-(2 hydroxyethyl)-3-thiazoliomethyl]-3-cephem-4 carboxylate (syn isomer), mp 150 to 1550C (dec.). IR (Nujol) : 3330, 1780, 1670, 1610, 1530 cm 1 (20) 7- [2- (2-Cyclopenten-l-yloxyimino) -.2- (5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl 1-pyridiniomethyl) -3-cephem-4-carboxylate (syn isomer), mp 140 to 1450C (dec.). IR (Nujol) : 3300, 3200, 1770, 1660, 1620, 1520 cm¯l (21) 7-[2-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-2-yl)acetamido]-3-(3 hydroxymethyl-l-pyridiniomethyl) -3-cephem-4 carboxylate (syn isomer), mp 143 to 1480C (dec.). IR (Nujol) : 3300, 3200, 1770, 1660, 1610, 1520 cm-Ú (22) 7-[2-Carboxymethoxyimino-2-(5-amino-1,2,4 thiadiazol- 3-yl) acetamido] - 3- (3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 170 to 175 C (dec.). IR (Nujol) : 3300, 1770, 1670, 1620, 1525 cm 1 (23) 7-[2-Ethoxycarbonylmethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(3 hydroxymethyl-1-pyridiniomethyl)-3-cephem-4 carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3400-3150, 1770, 1670, 1610 cm NMR (DMSO-d6+D2O, #) : 1.23 (3H, t, J=7Hz) 3.11, 3.67 (2H, ABq, J=18Hz)] 4.23 (2H, q, J=7Hz), 4.82 (411, bs), 5.17 (1H, d, J=5Hz), 5.30, 5.73 (2H, ABq, J=13Hz), 5.83 (1H, d, J=5Hz), 8.17 (111, m), 8.60 (1H, m), 9.23 (2H, m) (24) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3-mesylamino-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp 170 to 1750C (dec.). IR (Nujol) : 3400, 1760, 1670, 1610, 1520, 1150 cm-Ú (25) 7-[2-(1-Methyl-1-ethoxycarbonylethoxyimino)-2 (5-amino-1,2,4-thiadiazol-3-yl)acetamido[-3 (3-hydroxymethyl-1-pyridiniomethyl)-3-cephem 4-carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3400-3200, 1780, 1740, 1680 cm NMR (DMSO-d6+D2O, d) : 1.16 (3H, t, J=7Hz), 1.48 (6H, s), 3.16, 3;62 (2H, ABq, J=18Hz), 4.16 (2H, e, J=7Hz), 4.80 (2H, s), 5.14 (1H, d, J=5Hz), 5.2-5.8 (2H, m), 5.80 (1H, d, J=5Hz), 8.20 (1H, m), 8.56 (1H, m), 9.32 (2H, m) (26) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]-3-(3-thiazoliomethyl)-3-cephem 4-carboxylate (syn isomer), mp 155 to 1600C (dec.). IR (Nujol) : 3400-3200, 1770, 1660, 1600, 1520 cm (27) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]-3-[4-(N-hydroxycarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 178 to 185 C (dec.). IR (Nujol) : 3250, 3180, 1770, 1670, 1640, 1605, 1530 cm (28) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-butoxycarbonyl-1-pyridinio metRyl)-3-cephem-4-carboxylate (syn isomer), mp 154 to 1590C (dec.). IR (Nujol) : 3300, 3160, 1775, 1728, 1670, 1605, 1525 cm-Ú (29) 7- [2-Ethoxyimino-2-(5-mino-1,2,4-thiadiazol-3- yl)acetamido]-3-(4-t-butoxycarbonyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 154 to 1570C (dec.). IR (Nujol) : 3300, 3150, 1775, 1725, 1670, 1610, 1525 cm-Ú (30) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol- 5-yl)acetamido]-3-[4-butylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 161 to 1620C (dec.). IR (Nujol) : 3270, 1775, 1655, 1610, 1560, 1530 cm 1 (31) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-[4-(N-t-butylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 165 to 1670C (dec.). IR (Nujol) : 3270, 1775, 1660, 1610, 1530 cm 1 (32) 7-[2-Ethoxyimino-2-(5-amino-1,2,4,-thiadiazol 3-yl)acetamido]-3-(4-dodecyloxycarbonyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp 152 to 157 C (dec.). IR (Nujol) : 3280, 3160, 1775, 1730, 1675, 1610, 1520 cm (33) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl]acetamido]-3-[4-(N-dodecylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 176 to 1770C (dec.). IR (Nujol): 3270, 1770, 1655, 1610, 1540 cm 1 (34) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl0acetamido]-3-(4-octyloxycarbonyl-1-pyridinio methyl)-3-cephem-4-carboxylate (syn isomer), mp 155 to 158 C (dec.). IR (Nujol) : 3270, 1775, 1735, 1680, 1615, 1520 cm (35) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-[4-(N-octylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp 181 to 1830C (dec.). IR (Nujol) : 3250, 1770, 1655, 1610, 1565, 1550, 1530 cm (36) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]-3-(4-ethoxycarbonyl-1 pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), mp 150 to 1550C (dec.). IR (Nujol) : 3320, 3160, 1775, 1730, 1670, 1610, 1530, 1290 cm-Ú NMR (DMSO-d6+D2O,#) : 1.21 (3H, t, J=7Hz), 1.36 (3H, t, J=7Hz), 3.12, 3.52 (2H, ABq, J=18Hz), 4.12 (2H, q, J=7Hz) 4.43 (2H, q, J-7Hz), 5.06 (1H, d, J=5Hz), 5.33, 5.68 (211, ABq, J=14Hz), 5.71 (1H, d, J=5Hz), 8.47 (2H, d, J=6Hz), 9.60 (2H, d, J=611z) Example 12 To a cold mixture of trifluoroacetic acid C14 ml) and anisole (2.5 ml) was added 7-[2-t-butoxycarbonyl- methoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamino]-3-(3-hydroxymethyl-1-pyridiniomethyl)-3cephem-4-carboxylate (syn isomer) (2.0 g) under stirring and the mixture was stirred for 80 minutes at room temperature. The mixture was evaporated to remove trifluoroacetic acid and the residue was triturated with isopropyl alcohol to give a powder. The powder was dissolved in water. The aqueous solution was subjected to a column chromatography on a non ionic adsorption resin "Diaion HP-20" (100 ml). After the column was washed with water, the elution was carried out with 15% aqueous methanol. The eluates containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2-carboxymethoxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl-1pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer) (1.05 g), mp 170 to 1750C (dec.). IR (Nujol) : 3300, 1770, 1670, 1620, 1525 cm 1 NMR (DMSO-d6+D2O, 6) : 3.20, 3.50 (2H, ABq, J=18Hz), 4.63 (2H, s), 4.73 (2H, s), 5.07 (1H, d, J=4Hz), 5.27, 5.60 (2H, ABq, J=14Hz), 5.87(1H, d, J=4Hz), 7.90-8.17 (1H, m), 8.37-8.60 (111, m), 9.0-9.3 (2H, m) Preparation 13 To a solution of phosphorus pentachloride (54.6 g) in methylene chloride (500 ml) was added 2-ethoxyimino2-(5-amino-1,2,4-thiadiazol-3-yl)acetic acid (syn isomer) (54.0 g) under stirring and cooling at -20 C. The mixture was stirred for 30 minutes at -15 to -120C and for 2 hours at -50C. To the mixture containing precipitates of an object compound was added diisopropyl ether (500 ml) at -50C and the mixture was stirred for 30 minutes at -5 to 100C. The resulting precipitates were collected by filtration, washed with diisopropyl ether and dried to give 2-ethoxyimino-2-(5amino-1,2,4-thiadiazol-3-yl)acetyl chloride hydrochloride (syn isomer) (60.17 g), mp. 125 to 1270C (dec.). I.R. (Nujol) : 1785, 1625, 1055 cm 1 Analysis for C6H8O2N4SCl2 C H N S C1 calc'd : 26.57 2.95 20.66 11.81 26.20 found : 26.13 2.99 20.49 11.77 26.41 Preparation 14 To a suspension of diphenylmethyl 7-amino-3chloromethyl-3-cephem-4-carboxylate hydrochloride (27 g) in methylene chloride (300 ml) was added N,N-dimethylaniline (36.2 g) under cooling in an ice bath at 5 C. To the solution was added portionwise 2-ethoxyimino 2-(5-amino-1,2,4-thiadiazol-3-yl)acetyl chloride hydrochloride (syn isomer) (16.2 g) below 110C and the mixture was stirred for 45 minutes at 50C. The reaction mixture was diluted with a mixed solvent of methylene chloride (100 ml) and water (200 ml) and adjusted to pH 2 with 1N hydrochloric acid. The organic layer was separated out, washed with water, dried over magnesium sulfate and evaporated to dryness. The residue was triturated in diethyl ether to give diphenylmethyl 7-[2-ethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-chloromethyl-3-cephem-4carboxylate (syn isomer) (32.4 g), mp. 120 to 1250C (dec.). I.R. (Nujol) : 3300, 3150, 1780, 1725, 1675, 1625, 1530, 1495 cm 1 N.M.R. (DMSO-d6, 6) : 1.28 (311, t, J=7Hz), 3.68 (2H, broad s), 4.23 (2H, q, J=7Hz), 4.47 (2H, s), 5.27 (1H, d, J=5Hz), 5.97 (1H, 2d, J=5 and 8Hz), 7.0 (1H, s), 7.2-7.7 (10H, m), 8.17 (2H, broad s), 9.62 (1H, d, J=8Hz) Preparation 15 To a cold solution of diphenylmethyl 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3 chloromethyl-3-r: ephem-4-carboxylate (syn isomer) (10 g) in a mixed solution of methylene chloride (100 ml) and acetic acid (10 ml) were added 30% hydrogen peroxide (1.84 ml) and sodium tungstate (0.3 g). The mixture was stirred for 45 minutes in an ice bath and poured into diethyl ether (300 ml). The precipitates were collected by filtration and washed with diethyl ether to give diphenylmethyl 7-[2 ethOxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3- chloromethyl-3-cephem-4-carboxylate-1-oxide (syn isomer) (8.9 g), mp 150 to 155 C (dec.). I.R. (Nujol) : 3280, 3170, 1785, 1723, 1667, 1628, 1530 cm 1 N.M.R. (DMSO-d6, 6) : 1.30 (3H, t, J=7Hz], 3.90 (2H, broad s), 4.23 (2H, q, J=7Hz), 4.58 (2H, broad s), 5.12 (1H, d, J=5Hz), 6.10 (1H, 2d, J=5 and 8Hz), 7.02 (1H, s), 7.20-7.73 (10H, m), 8.15 (2H, broad s), 9.00 (1H, d, J=8Hz) Preparation 16 To a cold solution of diphenylmethyl 7-[2-ethoxyimino2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3 chloromethyl-3-cephem-4-carboxylate-l-oxide (syn isomer) (9.85 g) in acetone (222 ml) was added sodium iodide (8.22 g) and the mixture was stirred for 2 hours under cooling in an ice bath. The solvent was evaporated under reduced pressure and the residue was dissolved in a mixture of methylene chloride (200 ml) and water (100 ml). The organic layer was separated out, washed with an aqueous solution of sodium thiosulfate and water successively, dried over magnesium sulfate and evaporated to dryness. The residue was triturated in diethyl ether to give diphenylmethyl 7-[2-ethoxy- imino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3iodomethyl-3-cephem-4-carboxylate-1-oxide (syn isomer) (10.39 g), mp. 159 to 163 C (dec.). I.R. (Nujol) : 3250, 3150, 1780, 1720, 1670, 1620, 1520 cm N.M.R. (DMSO-d6, 6) : 1.29 (3H, t, J=7Hz), 3.95 (2H, m), 4.25 (2H, q, J=7Hz), 4.50 (2H, m). 5.12 (1H, d, J=5Hz), 6.05 (1H, 2d, J=5 and 9Hz), 7.00 (1H, s), 7.4 (10H, m), 8.13 (2H, broad s), 8.96 (1H, d, J=9Hz) EMI64.1 A mixture of diphenylmethyl 7-[2-ethoxyimino-2- (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-iodomethyl- 3-cephem-4-carboxylate-l-oxide (syn isomer) (5.0 g) and 3-aminopyridine (0.717 g) in tetrahydrofuran (35 ml) was stirred for one hour at room temperature. The resulting precipitates were collected by filtration, washed with tetrahydrofuran and diethyl ether and dried to give diphenylmethyl 7-[2-ethoxyimino-2-(5- amino-1,2,4-thiadiazol-3-yl)-acetamido]-(3-amino1-pyridiniomethyl)-3-cephem-4-carboxylate-1-oxide iodide (syn isomer) (5.41 g), nip. 157 to 1620C (dec.). I.R. (Nujol) : 3400-3200, 1795, 1725, 1680, 1610, 1530, 1510, 1035, 705 cm 1 N.M.R. (DMSO-d6,6): 1.26 (3H, t, J=7Hz), 3.3-4.0 (2H, m), 4.19 (2H, q, J=7Hz), 5.08 (1H, d, J=511z), 5.35 (2H, broad s), 6.10 (1H, 2d, J=5 and 8Hz), 6.6 (2H, m), 6.92 (1H, s), 7.1-7.7 (12H, m). 7.9 (2H, m), 8.03 (2H, broad s), 8.93 (1H, d, J=8Hz) Preparation 18 To a mixture of diphenylmethyl 7-[2-ethoxyimino 2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-(3- amino-l-pyridiniomethyl)-3-cephem-4-carboxylate-1oxide iodide (syn isomer)(4.50 g) and N,N-dimethylaniline (1.34 g) in acetonitrile (45 ml) was dropped phosphorus trichloride (1.52 g) below 80C under stirring and cooling in an ice bath. The mixture was stirred for 70 minutes at the same temperature and diethyl ether (50 ml) was added thereto. The resulting precipitates were collected by filtration, washed with diethyl ether and dried to give diphenylmethyl 7-[2-ethoxyimino-2-(5amino-1,2,4-thiadiazol-3-yl)acetamido]-3-(3-amino1-pyridiniomethyl)-3-cephem-4-carboxylate iodide (syn isomer) (5.05 g), nip. 85 to 950C (dec.). I.R. (Nujol) : 3300, 3200, 1790, 1680, 1630, 1510, 1220, 1185 cm-Ú N.M.R. (DMSO-d6 + D2O, 6) : 1.23 (3H, t, J=.7Hz), 3.2-3.8 (2H, m), 4.13 (2H, q, J=7Hz), 5.0-5.8 (4H, m), 6.87 (1H, s), 7.1-7.8 (12H, m), 7.8-8.1 (2H, m) Preparation 19 A solution of diphenylmethyl 7-[2-ethoxyimino-2 (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-(3-amino 1-pyridiniomethyl) -3-cephem-4-carboxylate iodide (syn isomer) (4.9 g) in a mixed solvent (12 ml) of acetone and methanol (1:1) was subjected to a column packed with an ion-exchange resin [Amberlite IRA-400 (Trademark : prepared by Rohm @ Haas Co.) trifluoroacetate-form] (50 ml). The elution was carried out with the same solvent (100 ml) and the eluate was evaporated to dryness. The residue was triturated in diethyl ether to give diphemylmethyl 7-[2-ethoxy imino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetamido]- 3- (3-amino-1-pyridiniomethyl) -3-cephem-4-carboxylate trifluoroacetate (syn isomer) (3.72 g), mp. 125 to 1300C (dec.) I.R. (Nujol) : 3300, 3200, 1790, 1690-1620, 1510, 1200, 1180, 1035 cm-1 N.M.R. (DMSO-d6, 6) : 1.25 (3H, t, J=7Hz), 3.2-3.7 (2H, m), 4.19 (2H, q, J=7Hz), 5.1-5.5 (2H, m), 5.29 (1H, d, J=5Hz), 6.00 (1H, 2d, J=5 and 8Hz), 6.91 (lH, s), 7.1-7.7 (12H, m), 7.8-8.3 (4H, m), 9.73 (lH,. d, J=8Hz) Example 13 A mixture of diphenylmethyl 7-[2-ethoxyimino 2-f5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3-(3-amino- 1-pyridiniomethyl)-3-cephem-4-carboxylate trifluoracetate (syn isomer) (500 mg) and anisole (1.0 ml) in trifluoroacetic acid (3 ml) was stirred for 35 minutes under cooling in an ice-salt bath. The mixture was poured into cold diisopropyl ether (20 ml) under stirring and resulting precipitates were collected by filtration. The powder was suspended in water (18 ml), adjusted to pH 4 to 5 with aqueous solution of sodium bicarbonate and an insoluble material was filtered off. The filtrate was subjected to column chromatography on a non ionic adsorption resin "Diaion HP 20" (Trademark Prepared by Mitsubishi Chemical Industries) (20 ml). After the column was washed with water, the elution was carried out with 208 aqueous methanol. The eluates containing an object compound were collected, evaporated to remove methanol under reduced pressure and lyophilized to give 7-[2-ethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamidoJ-3-(3-amino-1- pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer) (100 mg), mp. 175 to 1800C (dec.). I.R. (Nujol) : 3300, 3200, 1770, 1660-1590, 1510, 1150, 1035 cm N.M.R. (DMSO-d6,S) : 1.24 (3H, t, J=7Hz), 3.04 and 3.53 (2H, ABq, J=18Hz), 4.16 (2H, q, J=7Hz), 5.06 and 5.61 (2H, ABq, J=14Hz), 5.10 (1H, d, J=5Hz), 5.73 (1H, 2d, J=5 and 8Hz), 6.6-7.2 (2H, m), 7.7 (2H, m), 8.22 (2H, broad s), 8.5-8.6 (2H, m), 9.51 (1H, d, J=8Hz) Example 14 The following compounds were obtained according to a similar manner to that of Example 13. (1) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-hydroxymethyl-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), mp. 160 to 1650C (dec.). -l I.R. (Nujol) : 3300, 1770, 1660, 1610, 1520 cm (2) Sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamido]-3-[4-(2-sulfonatoethyl) 1-pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 165 to 1710C (dec.). I.R. (Nujol) : 3500-3200, 1765, 1660, 1630, 1610, 1520 cm-1 (3) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-hydroxy-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer); mp. 175 to 1800C (dec.). I.R. (Nujol) : 3390, 3290, 3180, 3050, 1770, 1660, 1625, 1610, 1525 cm 1 (4) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-cyano-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp. 147 to 1510C (dec.). I.R. (Nujol) : 3400-3100, 1780, 1670, 1610, 1530, 1040 cm 1 (5) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-hydroxymethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp. 150 to 1550C (dec.). I.R. (Nujol) : 3250, 1770, 1660, 1630, 1605, 1570, 1520 cm 1 (6) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(4-carboxy-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), mp 175 to 1850C (dec.). I.R. (Nujol): 3400-3150, 1780, 1670, 1630, 1560, 1530, 1040 cm 1 (7) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-t4-(3-hydroxypropyl)-1-pyridinio- methyl]-3-cephem-4-carboxylate (syn isomer), mp. 159 to 1670C (dec.). -l I.R. (Nujol) : 3400-3100, 1770, 1670-1610, 1540 cm (8) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-(3-chloro-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp. 210 to 2200C (dec.). I.R. (Nujol) : 3400-3100, 1770, 1660, 1610, 1520 cm 1 (9) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3-methyl-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp. 175 to 1800C (dec.). I.R. (Nujol) : 3280, 1770, 1660, 1610, 1530, 1035 cm-Ú (10) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido-3-(3,5-dimethyl-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp. 165 to 175 C (dec.) I.R. (Nujol) : 3400-3150, 1770, 1660, 1610, 1530 -1 (11) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-(4-aminomethyl-1-pyridiniomethyl)- 3-cephem-4-carboxylate diformate (syn isomer), mp. 149 to 1590C (dec.). I.R. (Nujol) : 3250, 3150, 1770, 1660, 1640, 1580, 1520, 1040 cm P (12) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-(4-t-butyl-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), mp. 169.5 to 175.0 C (dec.). I.R. (Nujol) : 3280, 1770, 1670, 1630, 1610, 1530 cm-Ú (13) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 155 to 1600C (dec.). -l I.R. (Nujol) : 3350, 3200, 1775, 1670, 1615, 1525 cm (14) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 160 to 1650C (dec.). I.R. (Nujol) : 3260, 3170, 1770, 1655, 1610, 1520 cam 1 (15) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-acetyl-1 pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 145 to 1500C (dec.). I.R. (Nujol) : 3270, 1770, 1700, 1670, 1610, 1520 cm-Ú (16) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamido]-3-(3-carboxymethyl 1-pyridiniomethyl)-3-cephen-4-carboxylate (syn isomer), mp. 165 to 1700C (dec.). I.R. (Nujol) : 3350, 3200, 1775, 1720, 1670, 1620, 1525 cm 1 (17) 7-[2-Cyclopentyloxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(4-hydroxyiminomethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 140 to 1450C (dec.). I.R. (Nujol) : 3280, 3160, 1770, 1680, 1630, 1610, 1520 cm 1 (18) 7-[2-Cyclopentyloxyimino-2-(5-emino-1,2,4 thiadiazol-3-yl)acetamido]-3-[4-methyl-5(2 hydroxyethyl)-3-thiazoliomethyl]-3-cephem-4 carboxylate (syn isomer), mp. 150 to 155 C (dec.). I.R. (Nujol) : 3330, 1780, 1670, 1610, 1530 cm (19) 7-[2-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(4-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 140 to 1450C (dec.). I,R. (Nujol) : 3300, 3200, 1770, 1660, 1620, 1520 cm 1 (20) 7-[2-(2-Cyclopenten-1-yloxyimino)-2-(5-amino 1,2,4-thiadiazol-3-yl)acetamido]-3-(3 hydroxymethyl-1-pyridiniomethyl)-3-cephem-4 carboxylate (syn isomer), mp. 143 to 1480C (dec.). I.R. (Nujol) : 3300, 3200, 1770, 1660, 1610, 1520 cm-Ú (21) 7-[2-Carboxymethoxyimino-2-(5-amino-1,2,4 thiadiazol-3-yl)acetamido]-3-(3-hydroxymethyl 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 170 to 1750C (dec.). I.R. ( Nujol) : 3300, 1770, 1670, 1620, 1525 cm 1 (22) 7-[2-Ethoxycarbonylmethoxyimino-2-(5-amino 1,2,4-thiadiazol-3-yl0acetamido]-3-(3 hydroxymethyl-1-pyridiniomethyl)-3-cephem-4 carboxylate (syn isomer), mp. 155 to 1600C (dec.). I.R. (Nujol) : 3400-3150, 1770, 1670, 1610 cm 1 (23) 7-[2-Ethoxylimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-(3-mesylamino-1-pyridiniomethyl) 3-cephem-4-carboxylate (syn isomer), mp. 170 to 1750C (dec.). I.R. (Nujol) : 3400, 1760, 1670, 1610, 1520, 1150 cm 1 (24) 7-[2-(1-methyl-1-ethoxycarbonylethoxyimino)-2 (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3 (3-hydroxymethyl-l-pyridiniomethyl)-3-cephem- 4-carboxylate (syn isomer), mp. 155 to 1600C (dec.). I.R. (Nujol) : 3400-3200, 1780, 1740, 1680 cm 1 (25) 7- [2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetamido]-3-(3-thiazoliomethyl)-3-cephem 4-carboxylate (syn isomer), mp. 155 to 1600C (dec.). I.R. (Nujol) : 3400-3200, 1770, 1660, 1600, 1520 cm 1 (26) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetamido]-3- [4-(N-hydroxycarbamoyl)-l- pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 178 to 1850C (dec.). I.R. (Nujol) : 3250, 3180, 1770, 1670, 1640, 1605, 1530 cm 1 (27) 7- [2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamidl]-5-(4-butoxycarbonyl-1-pyridinio methyl)-3-cephem-4-carboxylate (syn isomer), mp. 154 to 1590C (dec.). I.R. (Nujol) : 3300, 3160, 1775, 1728, 1670, 1605, 1525 cm'l (28) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]-3-[4-(N-butylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 161 to 1620C (dec.). I.R. (Nujol) : 3270, 1775, 1655, 1610, 1560, 1530 cm'l (29) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-[4-(N-t-butylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 165 to 1670C (dec.). I.R. (Nujol) : 3270, 1775, 1660, 1610, 1530 cm 1 (30) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetamido]-3-(4-dodecyloxycarbonyl- pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 152 to 1570C (dec.). I.R. (Nujol) : 3280, 3160, 1775, 1730, 1675, 1610, 1520 cm-1 (31) 7-[-2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido)-3- [4-(N-dodecylcarbamoyl)-1- pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 176 to 177 C (dec.). I.R. (Nujol) : 3270, 1770, 1655, 1610, 1540 cm 1 (32) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3- yl)acetamido]-3-(4-octyloxycarbonyl-1-pyridinio methyl) -3-cephem-4-carboxylate (syn isomer), mp. 155 to 1580C (dec.). I.R. (Nujol) : 3270, 1775, 1735, 1680, 1615, 1520 cm 1 (33) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3 yl)acetamido]-3-[4-(N-octylcarbamoyl)-1 pyridiniomethyl]-3-cephem-4-carboxylate (syn isomer), mp. 181 to 1830C (dec.). I.R. (Nujol) : 3250, 1770, 1655, 1610, 1565, 1550, 1530 cm 1 (34) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetamido-3-(4-ethoxycarbonyl-l- pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), mp. 150 to 155 C (dec.). I.R. (Nujol) : 3320, 3160, 1775, 1730, 1670, 1610, 1530, 1290 cm-Ú Example 15 The following compounds were obtained according to similar manners to those of aforesaid Examples. (1) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-amino-1-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), mp. 175 to. 180 C (dec.). I.R. (Nujol) : 3300, 3200, 1770, 1660-1590, 1510, 1150, 1035 cm-Ú (2) 7-[2-Ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(4-hexadecyloxycarbonyl-1-pyridinio methyl)-3-cephem-4-carboxylate (syn isomer), mp. 161 to 1660C (dec.). I.R. (Nujol) : 3400, 3250, 1770, 1730, 1670, 1610, .1520, 1285, 1120, 1035 cm N.M.R. (DMSO-d6+D20,S) : 0.83 (3H, t, J=7Hz), 1.0-1.7 (29H, m), 3.2-3.8(2H7 m), 4.0-4.5 (4H, m), 4.9-5.3 (2H, m), 5.5-6.0(2H, m), 8.4 (2H, m), 9.4 (2H, m) Preparation 20 The following compound was obtained according to a similar manner to that of Preparation 3, Hexadecyl isonicotinate, mp. 60 to 630C. I.R. (Nujol) : 1722, 1560, 1480, 1410, 1290, 1275 cm 1 N.M.R. (DMSO-d6, #) : 0.7-1.8 (31H, m), 4.30 (2H, t, J=5Hz), 7.7 (2H, m), 8.7 (2H, m)

Claims: What we claim is: 1. New cephem compounds of the formula: EMI75.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo(lower)alkyl or cyclo(lower)alkenyl; and R3 is a thiazolio group which may be sub stituted with suitable substituent(s) or a pyridinio group substituted with sub stituent(s) selected from the group con sisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo (lower)alkyl, protected amino (lower) alkyl, amino (lower) alkyl, carboxy(lower)alkyl and hydroxyimino (lower) alkyl; ; and pharmaceutically acceptable salts thereof. 2. Syn isomer of a compound of claim 1. 3. A compound of claim 2, wherein EMI75.2 4. A compound of claim 3, wherein R1 is amino; R2 is lower aliphatic hydrocarbon group which may be substituted with 1 to 3 substituent(s) selected from the group consisting of carboxy and protected carboxy, cyclo(lower)alkyl or cyclo(lower)alkenyl; and R3 is a thiazolio group which may be substituted with 1 to 3 substituent(s) selected from the group consisting of lower alkyl and hydroxy(lower)alkyl or a pyridinio group substituted with 1 to 3 substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)alkyl, protected amino(lower)alkyl, amino(lower)alkyl, carboxy(lower) alkyl and hydroxyimino (lower) alkyl. 5. A compound of claim 4, wherein R2 is lower alkyl which may be substituted with 1 substituent selected from the group consisting of carboxy and protected carboxy, cyclo(lower)alkyl or cyclo (lower) alkenyl. 6. A compound of claim 5, wherein R2 is lower alkyl or cyclo(lower)alkyl and R3 is a thiazolio group which may be substituted with one lower alkyl and one hydroxy(lower)alkyl. 7. A compound of claim 6, wherein R2is ethyl or cyclopentyl and R3 is a thiazolio group or a thiazolio group substituted with one methyl and one hydroxyethyl. 8. A compound of claim 7, which is selected from the group consisting of: 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-thiazoliomethyl)-3-cephem-4-carboxylate (syn isomer) and 7-[2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido] -3- [4-methyl-S- (2-hydroxyethyl) -3- thiazoliomethyl) -3-cephem-4-carboxylate (syn isomer). 9. A compound of claim 5, wherein R3 is a pyridinio group substituted with 1 to 2 substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, lower alkanesulfonyl amino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, alkoxycarbonyl, lower alkyl, hydroxy(lower) alkyl, sulfo (lower) alkyl, lower alkoxycarbonylamino (lower) alkyl, amino(lower)alkyl, carboxy(lower)alkyl and hydroxyimino (lower) alkyl. 10. A compound of claim 9, wherein R2 is ethyl, carboxymethyl, ethoxycarbonylmethyl, t-butoxycarbonylmethyl, l-methyl-l-ethoxycarbonyl ethyl, cyclopentyl or 2-cyclopenten-l-yl and R3 is a pyridinio group substituted with 1 to 2 substituent(s) selected from the group consisting of chloro, cyano, hydroxy, amino, mesylamino, acetyl, hydroxycarbamoyl, butylcarbamoyl, t-butylcarbamoyl, octylcarbamoyl, dodecylcarbamoyl, carboxy, ethoxy carbonyl, butoxycarbonyl, t-butoxycarbonyl octyloxy carbonyl, dodecyloxycarbonyl, hexadecyloxycarbonyl, methyl, t-butyl, hydroxymethyl, 3-hydroxypropyl, 2-sulfoethyl, t-butoxycarbonylaminomethyl, aminomethyl, carboxymethyl and hydroxyiminomethyl. 11. A compound of claim 10, which is selected from the group consisting of 7- [2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-hydroxymethyl-l-pyridiniomethyl)-3 cephem-4-carboxylate (syn isomer), 7- [2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-hydroxymethyl-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-cyano-1-pyridiniomethyl)-3-cephem4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-aminomethyl-1-pyridiniomethyl)-3 cephem-4-carboxylate diformate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-chloro-1-pyridiniomethyl)-3-cephem-4- carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3,5-dimethyl-l-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-t-butyl-1-pyridiniomethyl)-3-cephem- 4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-ls2s4-thiadiazol-3-yl)- acetamido]-3-(3-methyl-l-pyridiniomethyl 3-cephem-4- carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(3-hydroxy-1-pyridiniomethyl)-3-cephem- 4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(3-hydroxyopropyl)-1-pyridiniomethyl]3-cephem-4-carboxylate (syn isomer), sodium 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(2-sulfonatoethyl)-1-pyridiniomethyl]3-cephem-4-carboxylate (syn isomer), 7-[2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido]-3-(3-hydroxymethyl-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), 7- [2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido) -3- (4-dodecyloxycarbonyl-l-pyridiniomethyl) -3- cephem-4-carboxylate (syn isomer), 7- [2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-carboxy-1-pyridiniomethyl)-3-cephem-4carboxylate (syn isomer), 7- [2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl)acetamido) -3- (4-hydroxymethyl-l-pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), 7-[2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetami-do]-3-(4-acetyl-1-pyridiniomethyl) -3cephem-4-carboxylate (syn isomer), 7-[2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl) acetamido]-3-(3-carboxymethyl-1-pyridiniomethyl)- 3-cephem-4-carboxylate (syn isomer), 7- [2-cyclopentyloxyimino-2-(5-amino-1,2,4-thiadiazol- 3-yl) acetamido]-3-(4-hydroxyiminomethyl-l-pyridinio- methyl)-3-cephem-4-carboxylate(syn isomer), 7- [2-(2-cyclopenten-1-yloxyimino)-2-(5-amino-1,2,4- thiadiazol-3-yl) acetamido]-3-(4-hydroxymethyl-1- pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), 7- [2-(2-cyclopenten-1-yloxyimino)-2-(5-amino-1,2,4- thiadiazol-3-yl) acetamido]-3-(3-hy droxymethyl- 1-pyridiniomethyl)-3-cephem-4-carboxylate (syn isomer), 7-[2-carboxymethoxyimino-2-(5-amino-1,2,4-thiadiazol 3-yl)acetamido] -3- (3-hydroxymethyl-1-pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxycarbonylmethoxyimino-2-(5-amino-1,2,4- thiadiazol-3-yl)acetamdo]-3-(3-hydroxymethyl l-pyridiniomethyl) -3-cephem-4-carboxylate (syn isomer), 7-[2-(1-methyl-1-ethoxycarbonylethoxyimino)-2 (5-amino-1,2,4-thiadiazol-3-yl)acetamido]-3 (3-hydroxymethyl-1-pyridiniomethyl)-3-cephem-4carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3- [4-(N-hydroxyzarbamoyl)-l-pyridinio- anethyl]-3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-butoxycarbonyl-1-pyridiniomethyl)¯ 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-t-butoxycarbonyl-1-pyridiniomethyl)- 3-cephem-4-carboxylate (syn isomer) 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamidol-3-[4-(N-butylcarbamoyl) I-pyridiniomethyl]- 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(N-t-butylcarb amoyl)-l-pyridinio- methyl)-3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(N-dodecylcarbamoyl)-l-pyridiniomethyl3- 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-amino-1-pyridiniomethyl)-3-cephem-4- carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,J,4-thiadiazol-3-yl)- acetamido) -3- (4--octyloxycarbonyl-l-pyridiniomethyl) - 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-[4-(N-octylcarbamoyl)-l-pyridiniomethyl]- 3-cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido]-3-(3-mesylamino-1-pyridiniomethyl)-3- cephem-4-carboxylate (syn isomer), 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)- acetamido]-3-(4-ethoxyzarbonyl-1-pyridiniomethyl)- 3-cephem-4-carboxylate (syn isomer), and 7-[2-ethoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl) acetamido] - 3- (4-hexadecyloxycarbonyl-l-pyridiniomethyl) - 3-cephem*4-carboxylate (syn isomer). 12. A process for preparing new cephem compounds of the formula EMI81.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo(lower)alkyl or cyclo(lower) alkenyl; and R3 is a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo (lower) alkyl, protected amino(lower) alkyl, amino(lower)alkyl, carboxy(lower)alkyl and hydroxyimino (lower) alkyl; or pharmaceutically acceptable salts thereof, which comprises reacting a compound of the formula EMI82.1 wherein R1 and R2 are each as defined above; and R4 is a group which can be substituted with a group of the formula R3 wherein R3 is as defined above; or a salt thereof with a compound of the formula R3a wherein R3a is thiazole which may be substituted with suitable substituent(s) or pyridine substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxy carbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)alkyl, protected amino (lower) alkyl, amino(lower)alkyl, carboxy(lower) alkyl and hydroxyimino(lower) alkyl. 13. A process for preparing new cephem compounds of the formula EMI83.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo (lower) alkyl or cyclo (lower) alkenyl; and R3 is a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower) alkyl, sulfo(lower)alkyl,- protected anino(lower)alkyl ,aminolower) alkyl, - -carboxy (lcawer) àlkyI- and hydroxyimino (lower) alkyl or pharmaceutically acceptable salts thereof, which comprises reacting a compound of the formula EMI83.2 where in R3 is as defined above; or its reactive derivative at the amino group or a salt thereof with a compound of the formula EMI84.1 wherein R1 and R2 are each as defined above; or its reactive derivative at the carboxy group or a salt thereof. 14. A process for preparing new cephem compounds of the formula EMI84.2 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo (lower) alkyl or cyclo(lower) alkenyl; and R3c is a pyridinio group substituted with amino(lower)alkyl; or pharmaceutically acceptable salts thereof, which comprises subjecting a compound of the formula EMI84.3 wherein R1 and R2 are each as defined above and R3b is a pyridinio group substituted with protected amino(lower) alkyl, or a salt thereof, to elimination reaction of amino-protective group. 15. A process for preparing new cephem compounds of the formula EMI85.1 wherein R1 is amino or a protected amino group; R2b is carboxy(lower)alkyl; and R3 is a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl , - alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)alkyl, protected amino(lower)alkyl, amino (lower) alkyl, carboxy (lower) alkyl and hydroxyimino (lower) alkyl; ; or pharmaceutically acceptable salts thereof, which comprises subjecting a compound of the formula EMI85.2 wherein R1 and R3 are each as defined above and R2a is protected carboxy(lower)alkyl, or a salt thereof, to elimination reaction of carboxy-protective group, 16. A process for preparing new cephem compounds of the formula EMI86.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo (lower) alkyl or cyclo (lower) alkenyl; and R3 is a thiazolio group which may be substituted with suitable substituentCs) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)alkyl, protected amino(lower)alkyl, amino (lower) alkyl, carboxy(lower)alkyl and hydroxyimino (lower) alkyl; or pharmaceutically acceptable salts thereof, which comprises subjecting a compound of the formula EMI86.2 wherein R1, R2 and R3 are each as defined above, R5 is a protected carboxy group and X is an acid residue, to elimination reaction of carboxy-protective group. 17. A pharmaceutical antibacterial composition comprising a compound of claim 1 in association with a pharma ceutically acceptable, substantially non-toxic carrier or excipient. 18. A method for producing a pharmaceutical antibacterial composition which'comprises mixing a compound of claim 1 as an active ingredient with an inert carrier. 19. A compound of the formula EMI87.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo (lower) alkyl or cyclo (lower) alkenyl, R5 is a protected carboxy group; is is halogen, a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower)alkyl, protected amino (lower) alkyl, amino (lower) alkyl, carboxy(lower) - alkyl and hydroxyimino(lower)alkyl; and EMI87.2 and salts thereof. 20. A process for preparing a compound of the formula EMI88.1 wherein R1 is amino or a protected amino group; R2 is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo(lower)alkyl or cyclo(lower) alkenyl; R3 is a thiazolio group which may be substituted with suitable substituent(s) or a pyridinio group substituted with substituent(s) selected from the group consisting of halogen, cyano, hydroxy, amino, acylamino, lower alkanoyl, hydroxycarbamoyl, alkylcarbamoyl, carboxy, protected carboxy, lower alkyl, hydroxy(lower)alkyl, sulfo(lower) alkyl, protected amino(lower)alkyl, amino (lower) alkyl, carboxy (lower) alkyl and hydroxyimino (lower) alkyl; R5 is a protected carboxy group; and X is an acid residue; or salts thereof; which comprises reducing a compound of the formula EMI88.2 wherein R1, R2, R3, R5 and X are each as defined above, or a salt thereof.

Inventors: GOTO, JIRO, SAKANE, KAZUO, TERAJI, TSUTOMU
Applicants: FUJISAWA PHARMACEUTICAL CO., LTD.
Application year: 1981
Main classification: C07D501
IPC codes: C07D501, C07D285, C07D257, C07D295, C07C17