BETA-LACTAM COMPOUNDS AND PROCESS FOR THE PREPARATION THEREOF

Abstract: There are disclosed a compound having the following formula: in which R¹ denotes a substituted or unsubstituted thiazolyl radical, a substituted or unsubstituted thiazolylmercapto radical or a substituted or unsubstituted phenyl radical; R² denotes a halogen atom, a cyano radical, a carbamoyl radical, a lower-alkylmercapto radical or an O-lower-alkylcarboxyimidoyl radical; and Y represents a group (wherein R³ denotes hydrogen, a salt forming cation or a protective group for a carboxylic acid, and R⁴ denotes hydrogen or a residue of a nucleophilic compound); process for preparing the same; and an intermediate compound useful for preparing the same. The above mentioned compound has a broad antibacterial spectrum and shows strong antibacterial activities against not only gram-positive bacteria but also gram-negative bacteria, particularly the resistive gram-negative becteria.

Description: ss-Lactam compounds, process for the preparation thereof and intermediate products for the preparation thereof This invention relates to novel S-lactam compounds, a process for the preparation of these compounds, and intermediate products useful for synthesizing these compounds. Penicillin and cephalosporin compounds show broad anti- bacterial activities against gram-positive and gramnegative bacteria. Thus, several types of semi-synthetic penicillin and cephalosporin compounds are sold commercially and used as medicines for various infectious diseases in clinical applications. However, there are only a few medicine that can show antibacterial activities against Pseudomonas aeruginosa, Proteus vZgaris or the like which are causative of clinically serious infectious deseases. In addition, some of the above-mentioned commercially available agents are relatively unstable against ss-lactamase generated by resistant strains of bacteria These agents are also inadvantageous in that they show only a low antibacterial activity against agent-resistant bacteria, arousing problems in clinical applications (w. E. Wick, Cephalosporins and Penicillins, Chemistry and Biology, E. H. Flynn, Academic Press, New York. N. v , 1972, Chapter 11). Accordingly, there has been continuous search for ss-lactam compounds that have effective antibacterial properties against such pathogens, and there is a need for novel and effective ss-lactam compounds. An object of this invention is to provide ss-lactam compounds useful as antibacterial agents. Another object of this invention is to provide a novel process for preparing such useful ss-lactam compounds. A further object of this invention is to provide intermediate products which are useful for the synthesis of the aforesaid B-lactam compounds or other useful compounds. The novel B-lactam compounds provided according to this invention are defined by the following general formula (I]: EMI2.1 in which R1 denotes a substituted or unsubstituted thiazolyl radical, a substituted or unsubstituted thiazolylmercapto radical or a substituted or unsubstituted phenyl radical; R2 denotes a halogen atom, a cyano radical, a carbamoyl radical, a lower-alkylmercapto radical or an O-lower-alkylcarboxyimidoyl radical; and Y represents a group EMI2.2 (wherein R3 denotes hydrogen, a salt-forming cation or a protective group for a carboxylic acid, and R4 denotes hydrogen or a residue of a nucleophilic compound). The inventors have succeeded in synthesizing the ss-lactam compounds defined by general formula [I], and found out, as shown in the Test Example mentioned below, that these compounds have a broad antibacterial spectrum and show strong antibacterial activities against not only the grampositive bacteria but also the gram-negative bacteria, particularly the above-mentioned Pseudomonas aeruginosa, Proteus vuZgaris and Escherichia coZi, which arouse problems in clinical applications. It has also been found out that these S-lactam compounds according to this invention show extremely powerful antibacterial activities against the resistive gram-negative bacteria. The compounds of this invention represented by the above general formula [I] will be explained in more detail as follows. In the compounds according to this invention, there exist stereoisomers caused by the double bond on the carbon atom to which the substituent radical R2 is bonded. As examples for the substituent in R1 of the formula, there may be mentioned an amino radical, a protected amino radical, a halogen atom, a nitro radical, a cyano radical, a hydroxy radical, a lower-alkyl radical, a lower-alkoxy radical and a lower-alkylmercapto radical, etc. Rê represents a halogen atom such as a chloride atom or a bromine atom, a cyano radical, a carbamoyl radical, a lower-alkylmercapto radical such as a methylmercapto radical or an ethylmercapto radical, or an O-lower-alkyl carboxyimidoyl radical such as an O-methylcarboxyimidoyl radical which is represented by the radical of EMI3.1 R3 represents a hydrogen atom, a salt-forming cation or a protective radical for a carboxylic acid. Examples of the cations which R3 represents include those forming alkaline metal salts, alkaline earth metal salts, ammonium salts, etc. The protective radical which R3 represents may be any radicals that are normally used for this purpose in the conventional penicillin and cephalosporin compounds, such as alkyl, lower alkoxymethyl, lower alkylthiomethyl, lower alkanoyloxymethyl, aralkyl, aryl and silyl radicals, etc. R4 denotes hydrogen or a residue of a nucleophilic compound. The residue of a necleophilic compound may be, for example, hydroxyl; mercapto; optionally substituted lower aliphatic carboxylic acid acyloxy radicals having 2 to 4 carbon atoms such as acetyloxy, propionyloxy, 3oxobutyryloxy, 3-carboxypropionyloxy, 3-ethyloxycarbamoylpropionyloxy and 4-carboxybutyryloxy; optionally substituted aromatic carboxylic acid acyloxy radicals such as mandelyloxy, 2-carboxybenzoyloxy, 2-(carboethoxycarbamoyl)benzoyloxy and 2-(carboethoxysulfamoyl)benzoyloxy; carbamoyloxy; phenylglycyloxy, etc. These residues of nucleophilic compounds may further be substituted with alkyl and acyl radicals, etc. In this case, the number of the substituents is normally one or two. Alternatively, R4 the residue of a nucleophilic compound may be that of a quaternary ammonium salt, or may also denote a heterocyclic thio radical, that is, a heterocyclic ring which is bound via S (sulfer atom). In this context, the term "heterocyclic ring" means a 5- or 6-membered ring containing from 1 to 4 hetero atoms selected from the group consisting of O, S and N. The nitrogen atom(s) in the heterocyclic ring may optionally be in the form of N-oxide. Examples of such heterocyclic rings often used include pyridyl, N-oxidepyridyl, pyridazinyl, N-oxidepyridazinyl, pyrazolyl, diazolyl, thiazolyl, thiadiazolyl, oxadiazolyl, triazolyl, tetrazolyl, etc. These heterocyclic rings may optionally have substituents thereon, such as, e.g., lower alkyl having from 1 to 3 carbon atoms, lower alkoxy having from 1 to 3 carbon atoms, halogen atoms, trihalogeno-substituted lower alkyl, hydroxyl, mercapto, amino, carboxyl, carbamoyl, di-lower alkylamino lower alkyl having from 1 to 3 carbon atoms, carboxymethyl, etc. When the heterocyclic ring is substituted by such substituents, the number of substituents is normally one or two. The quaternary ammonium radical represented by R4 may be, for example, pyridinium, methylpyridinium, 3-chloropyridinium, 3-bromopyridinium, 3-iodopyridinium, 4-carbamoylpyridinium, 4-(N-hydroxymethylcarbamoyl)pyridinium, 4- (N-carbomethoxycarbamoyl) pyridinium, 4-(N-cyanocarbamoyl)pyridinium, 4-(carboxymethyl)pyridinium, 4-(hydroxymethyl)pyridinium, 4-(trifluoromethyl)pyridinium, quinolinium, purinium, lutidium, etc. In view of the antibacterial activity, preferable are ss-lactam compounds represented by the following formula [II] or [III]: EMI5.1 wherein R denotes hydrogen or a protective group for an amino radical, and Y has the same meaning as in formula [I], which has (Z)-Isomer structure, or EMI5.2 wherein R11 R2, R3, R4 and Y have the same meanings as in formula [I]. In the above formula tII], the term "(Z)-Isomer structure" means a structure in which the chlorine atom and the amido moiety take cis-configuration with respect to the double bond portion. R in the formula [II] denotes hydrogen or a protective group for an amino radical. The protective group for an amino radical means conventionally employing radicals as a protective group for an amino radical which is easily capable of release a radical by acidic hydrolysis or decomposition by adding water, such as tert-butoxycarbonyl radical, formyl radical, chloroacetyl radical, trityl radical and alkylsilyl radical. Next, specific compounds according to this invention will be exemplified as follows: Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl- 3-cephem-4-carboxylate (Isomer A) Sodium 7-[2-chlormethylene-2-(2-aminothiazol-4-yl)acetamido]desacetoxycephalosporanate (Isomer A) Sodium 7-12-chloromethylene-2-(2-aminothiazol-4-yl)- acetamidol-3-(1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem- 4-carboxylate (Isomer A) Disodium 7-[2-chlormethylene-2-(2-aminothiazol-4-yl) acetamidol-3-(2,5-dihydro-6-hydroxy-2-methyl-5-oXo-as- triazin-3-yl) thiomethyl-3-cephem-4-carboxylate (Isomer A) 7- (2-Chloromethylenephenylacetamido) -3- (1-methyl-lH- tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid (Isomer B) Sodium 7-[2-chloromethylene-3-(2-aminothiazol-5-yl)- mercaptoacetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl- 3-cephem-4-carboxylate 7-[2-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid (Isomer A and B) 7-[2-Methylmercaptomethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid (Isomer A and B) 7-[2-Cyanomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid (Isomer A) 7- [2- (o-Methylcarboxyimidoylmethylene)-2-(2- aminothiazol- 4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid 7-[2-Carbamoylmethylene-2-(2-aminothiazol-4-yl)acetamido] 3- (l-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (2-methylthio-l ,3 ,4-thiadiazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid (Isomer A) 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]cephalosporanic acid l-oxoisobenzofuran-3-yl ester (Isomer A) 7-[2-Chloromethylene-2-(2-aminOthiazol-4-yl)acetamidol- cephalosporanic acid pivaloyloxymethyl ester (Isomer A) 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido-3 (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4carboxylic acid Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido] -3-acetoxymethyl-3-cephem-4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-carbamoylmethyl-1,2,3,4-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylate (Isomer A) Disodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-methoxycarbonylmethyl-1,2,3,4-tetrazol5-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiozol-4-yl)- acetamido]-3-tl-hydroxyethyl-1,2,3,4-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-cyanomethyl-1,2,3,4-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1,2,3-thiadiazol-5-yl)thiomethyl-3-cephem4-carboxylate (Isomer A) Sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1,2,3-triazol-5-yl)thiomethyl-3-cephem-4carboxylate (Isomer A) Disodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(2-hydroxycarbonylmethylthio-1,3,4-thiadiazol 5-yl) thiomethyl-3-cephem-4-carboxylate (Isomer A) Sodium 7- [2-chloromethylene-2- (2-aminothiazol-4-yl) acetamido]-3-(2,5-dihydro-2-methyl-5-oxo-as-triazine-3-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A) 7-[2-Iodomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) Sodium 6- [2-chloromethylene-2- (2-aminothiazol-4-yl) - acetamido]penicillanate (Isomer A) The compounds of this invention can be prepared by reacting a compound having general formula [IV]: EMI9.1 (in which Y has the same meaning as defined above) a reactive derivative thereof with respect to the amino radical or a salt thereof, with an acid having general formula [V]: : EMI9.2 (in which R1 and R2 have the same meanings as defined above), a reactive derivative thereof with respect to the carboxyl radical or a salt thereof. The compounds represented by general formula [V], which are used as raw materials for the preparation of the compounds of this invention, can be prepared, for example, by reacting a R1-substituted glyoxylic acid derivative with a Wittig reagent such as halomethylenetriphenylphosphorane; by reacting a 2-formyl acetic acid derivative substituted by R1 radical, with a halogenating agent; or by isomerization reaction of the compound (V]. The acids represented by general formula [TV], which are used as raw materials for the preparation of the compounds according to this invention, are easily available commercially. Embodiments of the process for preparing the compounds according to this invention will now be described below. When the compounds represented by general formula [V] are to be used as a reactant in the form of free acids (or in the form of salts thereof), it is normally preferable that the reaction be carried out in the presence of a dehydrating or condensing agent such as N,N'-dicyclohexylcarbodiimide, N-cyclohexyl-N' -morpholinoethylcarbodiimide, N,N'-diethylcarbodiimide, N,N'-carbonyl(2-methylimidazole), trialkyl phosphate, polyphosphoric acid ethyl ester, phosphorus oxychloride, phosphorus trichloride, 2-chloro-1,3,2dioxaphospholane, oxalyl chloride, etc. Examples of the salts of the compounds represented by general formula [V] include alkaline metal salts, alkaline earth metal salts, ammonium salts, and salts with organic bases such as triethylamine, dicyclohexylamine, etc. As the reactive derivatives of the compounds represented by general formula [V], those reactive derivatives which are usually used in the synthesis of acid amides can be used. Examples of such reactive derivatives include acid halides, acid anhydrides, mixed acid anhydrides formed between organic or inorganic acids, active acid amides, acid cyanides, active esters, acid azides, etc. of the compounds represented by general formula [V). Acid chlorides, mixed acid anhydrides and active amides are particularly preferred. Examples of the mixed acid anhydrides include those of aliphatic carboxylic acids, aromatic carboxylic acids, alkylcarbonic acids, aralkylcarbonic acids, dialkylphosphoric acids, diphenylphosphoric acids, methanesulfonic acid, p-toluenesulfonic acid and the like. The active esters may be, for example, cyanomethyl esters, substituted phenyl esters, substituted benzyl esters, substituted thienyl esters, etc. The active acid amides may be, for example, imidazole, 4-substituted imidazole, dimethylpyrazole, triazole, tetrazole, saccharin and the like. The compounds represented by general formula [IV] are subjected to the reaction in the form of free form or in the form of salts or esters thereof. The salts of the compounds represented by general formula [IV] may be, for example, salts with organic acids such as acetates, benzenesulfonates, tartarates, trifluoroacetates, and formats: salts with inorganic acids such as hydrochlorides, hydrobromides, sulfates, and phosphates; alkaline metal salts such as sodium salts and potassium salts; and salts with organic bases such as trimethylamine salts, triethylamine salts and dibutylamine salts. Examples of the esters of the compounds represented by general formula [IV] include benzhydryl esters, trichloroethyl esters, pnitrobenzyl esters, alkylsilyl esters, etc. usually, the above-described reaction for preparing the compounds according to this invention is carried out in the presence of a solvent. The solvents may be any general organic solvents that do not participate in the reaction, such as dimethyl sulfoxide, methyl alcohol, ethyl alcohol, methoxyethanol, diethyl ether, isopropyl ether, benzene, toluene, methylene chloride, chloroform, ethyl acetate, methyl isobutyl ketone, etc. These solvents may be used in admixture with water. In addition, the reaction may be carried out in the presence of a base. Examples of such bases include inorganic bases such as caustic alkalis, alkali carbonates, alkali bicarbonates, and alkali acetates; tertiary amines such as trimethylamine, triethylamine, tributylamine, pyridine, N.-methylpiperidine,.N- methylmorpholine, lutidine and uridine; secondary amines such as diethylamine-, and dicyclohexylamine, etc. The reaction may be carried out at any temperature. Normally, however, it is conducted with cooling or at room temperature. Further, the compound represented by formula [I]according to this invention may be prepared by Wittig reaction in which a compound represented by general formula [VI]: EMI12.1 (in which R1 and Y have the same meanings as defined above), with a halomethylenetriphenylphosphorane, etc.; by reacting a compound represented by general formula [VII]: EMI12.2 (in which R1, R2 and R3 have the same meanings as defined above, and R5 denotes a residue of a nucleophilic compound), with a nucleophilic reagent; or by reacting a compound represented by general formula [VIII]: EMI13.1 (in which Y has the same meaning as defined above, and X denotes a chlorine atom or a bromine atom), with a thiourea compound. The ss-lactam compounds of this invention prepared in the manner described above may then be purified by a method known to the art, for example, by column chromatography, extraction, precipitation, recrystallization, etc. When necessary, the obtained 6-lactam compounds may be converted into a desired salt or an ester by a procedure known to the art. This invention further provides novel intermediate products, i.e., (2-formyl-2-(2-aminothiazol-4-yl)acetic acid derivatives) having the following general formula [IX]: EMI13.2 in which R has the same meaning as defined above, and R5 denotes an alkyl radical or an aryl radical. Examples of the compound represented by general formula [IX] include a 2-formyl-2-(2-substituted or unsubstituted aminothiazol-4-yl)acetic acid such as 2-formyl-2-(2 aminothiazol-4-yl) acetic acid, 2-formyl-2-(2-formylaminothiazol-4-yl)acetic acid, 2-formyl-2-(2-acetylaminothiazol-4-yl)acetic acid, 2-formyl-2-(2-chloroacetyl aminothiazol-4-yl) acetic acid, 2-formyl-2- (2-trifluoro- acetylaminothiazol-4-yl)acetic acid, 2-formyl-2-(2-t butoxycarbonylaminothiazol-4-yl) acetic acid, 2-formyl-2 (2-tritylaminothiazol-4-yl)acetic acid, 2-formyl-2-(2trialkylsilylaminothiazol-4-yl)acetic acid; and a 2formyl-2-(2-substituted or unsubstituted aminothiazol-4yl)acetate such as methyl, ethyl, t-butyl, benzyl, trichloroethyl, diphenylmethyl, phenyl and trialkylsilyl ester of the above-described compound. While the chemical structure of the intermediate products according to this invention has been shown by the structure of general formula lIX] which is a keto-form structure, it may either be represented by general formula [IX'] having an enol-form structure which is in chemical equilibrium with the keto-form structure. EMI14.1 The process for preparing 2-formyl-2-(2-aminothiazol-4yl)acetic acid derivatives represented by the above general formula [IX] is represented by the following reaction formula: Method A: EMI15.1 Method B: EMI15.2 Method C: EMI15.3 in which R5, R and X have the same meanings as defined above, and R6 and R7 each denote an alkyl radical or an aryl radical. Embodiments of the process for preparing the intermediate products will now be described below. [Method A] This method is to provide the intermediate product represented by general formula [IX] by reacting a 2- (2-amino- thiazol-4-yl) acetic acid derivative [X] with a formic acid ester. As to the synthesis of 2-(2-aminothiazol-4-yl)acetic acid derivative represented by general formula [IX], there are discribed, for example, in "Heterocyclic Compounds : Thiazole and Its Derivatives", Vol. 34, part 2; Edit. by J.V. Metzer, Wiley & Sons, p. 173. In this method, the presence of a base is indispensable requisites. As the base, there may widely be employed alkali metal such as sodium, potassium; alkali metal hydride such as sodium hydride and potassium hydride; alkali metal alkoxide such as sodium methoxide and potassium t-butoxide; and organic alkali metal compound such as n-butyl lithium and phenyl lithium. Equimolar to several times molar amout of the base with respect to the amount of the compound represented by general formula [X] is sufficient for the amount of the base to be used. When carrying out the reaction, it is preferable to use a solvent such as hydrocarbons, e.g. hexane, heptane, benzene and toluene; ethers, e.g. diethyl ether, tetrahydrofuran and dimethoxyethane; and polar solvents, e.g. dimethylformamide, dimethyl sulfoxide and hexamethylphosphoric triamide. The reaction may be conducted at a temperature ranging from OOC to the reflux temperature of the solvent used. However, the reaction proceeds smoothly at room temperature without using any special means for cooling or heating. [Method B] This method is to provide the intermediate product represented by general formula [IX] by reacting an ester of a y-halo- -formylacetoacetic acid represented by general formula IXI] with a thiourea compound represented by general formula [XII]. The compound of formula [XI] can be prepared by a well known method [for example, E. Benary and F. Ebert, Ber., 56B, 1897 (1923)], and may include, for example, a Y-chloro-a-formylacetoacetic acetate such as methyl Y-chloro-a-formylacetoacetate, ethyl r-chloro- a-formylacetoacetate, t-butyl Y-chloro-a-formylacetoacetate, benzyl Y-chloro-a-formylacetoacetáte, trichloroethyl y-chloro-a-formylacetoacetate diphenylmethyl ychloro-a-formylacetoacetate, phenyl Y-chloro-a-formyl acetoacetate; and y-bromo-a-formylacetoacetic acetates corresponding to those of the above-mentioned y-chloro-aformylacetoacetic acetates. On the other hand, the thiourea compound represented by general formula [XII] is thiourea or a thiourea derivative, and the thiourea derivative includes, for example, an N-substituted thiourea such as N-(2, 2, 2-trichloro- ethoxycarbonyl)thiourea. When carrying out the reaction, it is preferable to use a solvent such as water; alcoholic solvents, e.g., methanol and ethanol; and ether group solvents, e.g., tetrahydrofuran and dioxane. This reaction may be conducted at room temperature or under heating. [Method C] This method is to provide the intermediate product represented by general formula [XIV] by reacting a y -halo-cr -oxymethyleneacetoacetate represented by general formula [XIII], with the thiourea compound represented by formula [XII] (lust Step), and then hydrolyzing the resultant 2-oxymethylene-2-(2-aminothiazol-4-yl)acetic acid derivative represented by general formula [XIV] in an acidic condition (2nd Step). The compound of general formula [XIII] can be prepared by a well known method [for example, E. Benary and F. Ebert, Ber., 56B, 1897 (1923)], and may include, for example, a y y-chloro-a-oxymethylene- acetoacetate such as methyl y-chloro-a-methoxymethyleneacetoacetate, ethyl y-chloro-a-methoxymethyleneaceto- acetate, methyl y -chloro-a -ethoxymethyleneacetoacetate, ethyl y-chloro-a-ethoxymethyleneacetoacetate, benzyl ychloro-a-methoxymethyleneacetoacetate, benzyl y-chloro-a ethoxymethylene acetoacetate, trichloroethyl y-chloro-aethoxymethyleneacetoacetate, diphenylmethyl y-chloro-amethoxymethyleneacetoacetate, diphenylmethyl y-chloro-aethoxymethyleneacetoacetate; and a y-bromo-a-oxymethylene- acetoacetates corresponding to those of the abovementioned Y-chloro-a-oxymethyleneacetoacetates, On the other hand, the thiourea compound represented by general formula [XII] is thiourea or a thiourea derivative, and the thiourea derivative includes, for example, an Nsubstituted thiourea such as N-(2,2,2-trichloroethoxycarbonyl)thiourea. When carrying out the reaction of the 1st Step, it is preferable to use a solvent. Examples of the solvent includes the solvents exemplified in Method B, and the reaction may be conducted at room temperature or under heating. The 2nd Step is to hydrolyze 2-oxymethylene-2-(2-aminothiozol-4-yl)acetic acid derivatives under acidic conditions. As the acids to be used, there may be employed, for example, a mineral acid such as hydrochloric acid, sulfuric acid and perchloric acid; an organic acid such as formic acid, acetic acid, methanesulfonic acid and p-toluenesulfonic acid; phosphoric acid; a Lewis acid such as boron trifluoride, aluminum chloride, iron chloride and zinc chloride; a sulfate such as copper sulfate and zinc sulfate; and an acetate such as copper acetate and zinc acetate, etc. When carrying out the reaction of the 2nd Step, it is preferable to use a solvent. Examples of the solvent includes the solvents exemplified in Method B, and the reaction may be conducted at room temperature or under heating. As the bacteria and spirochaeta, against which the S- lactum compounds and their non-toxic salts of this invention act effectively, there may be exemplified the following: StaphyZococcus, Streptococcus, BaciZZus (BaciZZus anthracis, etc.), Corynebacterium (Corynebacterium diphtheriae, etc.), Mycobacterium (Mycobacterium tuberculosis, etc.), Neisseria (Neisseria gonorrhoeae, etc.), Pseudomonas (Pseudomonas aeruginosa, etc.), Escherichia (Escherichia coli, etc.), Citrobactor, SaZmoneZZa, ShigeZZa (ShigeZZa dysenteriae, etc.), KZebsieZZa (KZebsieZZa pneumoniae, etc.), Enterobactor, Serratia, Proteus, Vibrio (Vibrio cholerae, etc.), Bordet-Gengou bacillus (HaemophiZus pertussis, etc.), Haemophilus (Haemophilus inftuenzae, etc.), Brucella, HaemophiZus ducreyi (HaemophiZus ducreyi), CZostridium, Bacteroides, Fusobacterium, Peptococcus, Peptostreptococcus, Bubacterium, Propionibacterium, Spirochete. This invention will be explained in more detail by way of the following Examples, Synthesis Examples and Test Example, which however should not be construded to limit this invention. Synthesis Example 1 (1) A 50% suspension of sodium hydride (69.6 g, 1.45 mol) in oil was washed with n-hexane (200 mi x 2), and suspended in dried THF (435 mL). To this supension, there was added dropwise a solution of ethyl 2-(2-amino- thiazol-4-yl)acetate (135 g, 0.725 mol) and ethyl formate (107.3 g, 1.45 mol) in dried THF under stirring at room temperature. After the dropwise addition, stirring was continued for 14 hours, and the reaction mixture was adjusted to pH 7 by adding a 50% aqueous acetic acid solution. After the reaction mixture was extracted with ethyl acetate, the aqueous layer was further extracted with a mixed solvent of THF-ethyl acetate (1 : 1, 250 mQ x 2). Evaporation of the solvent under reduced pressure yielded ethyl 2-formyl-2-(2-formylaminothiazol-4-yl)- acetate (117.5 g, 67%) as white crystals. Melting point: 179 X 180 CC. IR (KBr): 3290, 1710, 1690, 1620 cm-l NMR dppm(CDCQ3-d6-DMSO): 1.33 (t, J=7Hz, 3H), 4.16 (q, J=7Hz, 2H), 7.50 (s, 1H), 8.00 (s, 1H), 8.53 (s, 1H). Mass m/e (%): 242 (M+, 32), 196 (95), 168 (100), 140 (71). Elemental analysis for CgHloN2OS4 Calculated: C, 44.62; H, 4.16; N, 11.56; S, 13.24 Found : C, 44.65; H, 4.13; N, 11.62; S, 13.34. (2) Ethyl 2-formyl-2-(2-formylaminothiazol-4-yl)acetate (1.0 g, 4.1 mmol) was dissolved in DMF (5 mL), and phosphorus oxychloride (0.78 g, 5.14 mmol) was added to the resultant solution. Subsequently the mixture was stirred under heating at 1000C for 1 hour. After the temperature of the reaction mixture was returned to room temperature, the mixture was adjusted to pH 7 by adding 1N aqueous sodium hydroxide solution. The mixture was extracted with ethyl acetate, and the extract was dried over magnesium sulfate. Evaporation of the solvent afforded DMF-containing ethyl 2-chloromethylene-2- (2- dimethylaminomethyleneaminothiazol-4-yl) acetate (Isomer A : B = 1 : 2.7) as an oily product(l.4 g). NMR dppm(CDCQ3): Isomer A: 1.40 (t, J=7Hz, 3H), 3.06 (d, J=2Hz, 6H), 4.40 (q, J=7Hz, 2H), 6.76 (s, 1H), 7.33 (s, 1H), 8.16 (s, 1H) Isomer B: 1.30 (t, J=7Hz, 3H), 3.10 (s, 6H), 4.26 (q, J=7Hz, 2H), 7.00 (s, 1H), 7.50 (s, 1H), 8.30 (s, 1H). (3) To an isomeric mixture of ethyl 2-chloromethylene2-(2-dimethylaminomethyleneaminothiazol-4-yl)acetate (1.4 g, Isomer A : B = 1 : 2.7), was added a mixed anhydride of formic acid and acetic acid (2.8 mQ), and the resulting mixture was stirred at room temperature for 2 days. After water was added to the reaction mixture, the solvent was removed by evaporation under reduced pressure. To the thus obtained residue was added ethyl acetate for extraction, and the extract was washed successively with an aqueous sodium hydrogen carbonate solution and water. The resulting extract was dried over sodium sulfate, and the solvent was removed by evaporation to obtain ethyl 2-chloromethylene-2-(2 formylaminothiazol-4-yl)acetate (1.2 g, Isomer mixture) Purification of the mixture by column chromatography afforded separately Isomer B (0.65 g) and Isomer A (0.19 g). Isomer B: Melting point: 103 Ç 1040C. IR (KBr): 1710, 1695, 1565, 1290, 1260 cm NMR dppm(CDCQ3): 1.26 (t, J=7Hz, 3H), 4.20 (q, J=7Hz, 2H), 7.14 (s, 1H), 7.60 (s, 1H), 8.48 (S, 1H), 12.22 (bs, 1H). Mass m/e (%): 260 (M+, 16) , 234 (21) , 232 (58) , 186 (24), 151 (100). Elemental analysis for C9H9ClN2O3S: Calculated: C, 41.46; H, 3.48; N, 10.75 Found : C, 41.55; H, 3.42; N, 10.80. Isomer A: Melting point: 140 X 1420C. IR (KBr): 1740, 1660, 1460, 1370, 1345, 1285, 1200, 1035 cm 1 NMR dppm(CDCQ3): 1.36 (t, J=7Hz, 3H), 4.34 (q, J=7Hz, 2H), 6.96 (s, 1H), 7.20 (s, 1H), 8.50 (s, 1H), 9.96 (bs, 1H). Mass m/e (%): 262 (9), 260 (M+, 25), 234 (21), 232 (56), 186 (22), 151 (100). Elemental analysis for C9H9CN2O3S: Calculated: C, 41.46; H, 3.48; N, 10.75 Found : C, 42.13; H, 3.63; N, 10.35. (4) Ethyl 2-chlormethylene-2-(2-formylaminothiazol-4yl)acetate (5.16 g, 0.0198 mol) (Isomer A) was suspended in 11 mQ of tetrahydrofuran, and to the suspension was added dropwise a solution of potassium hydroxide (3.32 g, 0.0594 mol) dissolved in water (55 ml) under ice-cooling. After the dropwise addition, the reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was extracted with a mixed solvent of ethyl acetate and ether (40 ml x 2, 1 : 1), and then the aqueous layer was separated and cooled to OOC. Then, the aqueous layer was adjusted to pH 2.0 with 2N hydrochloric acid. The precipitated crystals were collected by filtration, washed with water, air-dried and then dried over phosphorus pentoxide under reduced pressure to obtain pale-yellow powders (4.87 g). As a result of spectral analysis, it was found that the product contains deformylated form of the above-described carboxylic acid. After a mixed anhydride of acetic acid and formic acid (10 mQ) was added to the above powdery compound, the resulting mixture was stirred at room temperature for 4.5 hours. The reaction mixture was concentrated under reduced pressure, and the residue was washed with nhexane and dried over potassium hydroxide under reduced pressure to obtain 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A) as white powders (4.46 g, 97%). Melting point: 145 ¯ 1470C (decomposition). NMR dppm(d6-DMSO): 7.13 (s, 1H), 7.23 (s, 1H), 8.50 (s, 1H). IR (KBr): 3575, 3200, 3050, 2950, 2450, 1680, 1565 cm 1. Example 1 (1) After DMF (0.47 g, 6.45 mmol) was ice-cooled, phosphorus oxychloride (0.79 g, 5.16 mmol) was added thereto. The mixture was stirred at 500C for 30 minutes and thereafter THF (5 mQ) was added thereto to prepare the Vilsmeyer's reagent. A suspension of 2-chloromethylene2-(2-formylaminothiazol-4-yl)acetic acid (1.0 g, 4.3 mmol, Isomer A) in ethyl acetate (10 mQ) was cooled to -15 to -200C. To this reaction mixture was added dropwise the Vilsmeyer's reagent as prepared above. After the dropwise addition, the mixture was stirred at the same temperature for one hour. On the other hand, 7 amino-3- (2-methyl-l, 3, 4-thiadiazol-5-yl) thiomethyl-3- cephem-4-carboxylic acid (1.48 g, 4.3 mmol) was suspended in a mixed solvent of acetone-THF-water (2 : 2 1, 30 mQ). After cooled to OOC, the suspension was adjusted to pH 8 witha20% aqueous potassium carbonate solution. To this mixture was added dropwise the previously prepared mixture. During the dropwise addition, pH of the mixture was adjusted to 7.5 X 8.0 with the use of a 20% aqueous potassium carbonate solution. After the dropwise addition, the stirring was continued at 0 C for 1.5 hours, followed by evaporation of the solvent under reduced pressure. The residue was adjusted to pH 2.5 with 2N-HCQ. The precipitates were collected by filtration, washed with water and dried on air. The product was dissolved in THF (30 ml) and insolubles were removed by filtration. Evaporation of THF gave yellow powders (1.97 g), which were then charged with ethyl acetate (60 ml) and the mixture stirred for 30 minutes, followed by filtration. There was yielded as a powdery product 7 [2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A, 0.90 g). The filtrate was concentrated under reduced pressure to yield the cephem compound as described above (Isomer B, 0.45 g). NMR dppm(d6-DMSO): Isomer A: 2.66 (s, 3H), 3.66(qAB, J=18Hz, 2H), 4.20(qAB, J=1SHz, 2H), 5.20(d, J=4.5Hz, lH), 5.83 (dd, J=4.5Hz, J=9Hz, 1H), 7.03 (s, 1H), 7.06 (s, lH), 8.50 (bs, 1H), 9.63 (d; J=9Hz, 1H) Isomer B: 2.66 (s, 3H), 3.70(qAB, J=18Hz, 2H), 4.40(qAB, J=1SHz, 2H), 5.16(d, J=4.5Hz, 1H), 5.76 (dd, J=4.5Hz, J=9Hz, 1H), 7.20 (s, 1H), 7.60 (s, 1H), 8.53 (bs, 1H), 9.26 (d, J=9Hz, 1H). (2) 7-[2-Chlormethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid (Isomer A, 0.47 g, 0.84 mmol) was disso;ved in a mixed solvent of methanol-THF (1 : 1, 40 ml), and the resultant solution was cooled to 0 to 50 C. After 0.26 g (1.68 mmol) of phosphorus oxychloride was added dropwise to the solution, the mixture was further stirred for 2 hours. After the reaction, the mixture was adjusted to pH 3 with a saturated aqueous sodium hydrogen carbonate solution, followed by evaporation of the solvent under reduced pressure. The residue was ice-cooled and adjusted to pH 2.0. The precipitates were filtered and dried on air to yield 7-[2chloromethylene-2- (2-aminothiazol-4-yl) acetamido] -3- (2 methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4- carboxylic acid (Isomer A, 0.49 g) as pale yellow powders. NMR dppm(d6-DMSO): 2.66 (s, 3H), 3.70(qAB, J=18Hz, 2H), 4.33(qAB, J=13.5Hz, 2H), 5.12(d, J=6Hz, 1H), 5.66 (dd, J=6Hz, J=9Hz, 1H), 6.36 (s, 1H), 6.81 (s, 1H), 9.50 (d, J=9Hz, 1H) (3) 7- [2-Chloromethylene-2- (2-aminothiazol-4-yl) acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A, 0.49 g) was suspended in water (2 mQ) and the suspension was adjusted to pH 7.4 with a saturated aqueous sodium hydrogen carbonate solution to prepare a solution. This solution was purified by passing through the XAD-2 column to yield sodium 7 [2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4carboxylate (Isomer A) as white powders. NMR dppm(d6-DMso): 2.68 (s, 3H), 3.48(qAB, J=l7Hz, 2H), 4.46(qAB, J=12Hz, 2H), 5.06(d, J=5Hz, 1H), 5.63 (dd, J=5Hz, J=8Hz, 1H), 6.44 (s, 1H), 6.86 (s, 1H), 7.16 (bs, 2H), 9.50 (d, J=8Hz, 1H) Elemental analysis for C17H14C%N6O4S4Na.2H2O: Calculated: C, 34.67; H, 3.08; N, 14.27 Found : C, 34.56; H, 3.20; N, 13.72. Example 2 (1) After DMF (0.47 g, 6.45 mmol) was ice-cooled, phosphorus oxychloride (0.79 g, 5.16 mmol) was added thereto. The reaction mixture was stirred at 500C for 30 minutes and thereafter THF (10 m±) was added thereto prepare the Vilsmeyer's reagent. A suspension of 2 chloromethylene-2- (2-formylaminothiazol-4-y1) acetic acid (1.0 g, 4.3 mmol, Isomer A) in ethyl acetate (10 mQ) was cooled to -20 to -250C. To this mixture was added dropwise the Vilsmeyer's reagent as prepared above. After the dropwise addition, the mixture was stirred at the same temperature for ten minutes. On the other hand, 7-aminodesacetoxycephalosporanic acid (0.92 g, 4.3 mmol) was suspended in a mixed solvent of acetone-THF-water (2 : 2 : 1, 30 mQ). After cooled to 0 to -30C, the suspension was adjusted to pH 8 with a 20% aqueous potassium carbonate solution. To this mixture was added dropwise the previously prepared mixture over 20 minutes. During the dropwise addition, pH of the mixture was adjusted to 7.5 X 8.0 with the use of a 20% aqueous potassium carbonate solution. After the dropwise addition, the stirring was continued at OOC for one hour, followed by evaporation of the solvent under reduced pressure. The residue was extracted with ethyl acetate. The aqueous layer was separated and adjusted to pH 2.5 with 2N-HCQ. The precipitates were filtered, washed with water and dried on air. The product was dissolved in THF (20 mQ) and insolubles were removed by filtration. Evaporation of THF yielded 7-[2-chloromethylene-2-(2 formylaminothiazol-4-yl) acetamido] desacetoxycephalos- poranic acid as white powders (Isomer At 1.19 g). NMR 6ppm (d6-DMSO): 2.03 (s, 3H), 3.43 (qAB, J=18Hz, 2H), 5.13(d, J=6Hz, 1H), 5.73 (dd, J=6Hz, J=9Hz, 1H), 7.03 (s, 1H), 7.06 (s, 1H), 8.50 (s, 1H), 9.60 (d, J=9Hz, 1H) (2) Using 7-[2-chlormethylene-2-(2-formylaminothiazol4-yl)acetamido]desacetoxycephalosporanic acid (Isomer A), the reaction was carried out following the procedure of Example 1 - (2) to obtain 7-[2-chloromethylene-2-(2aminothiazol-4-yl) acetamido] desacetoxycephalosporanic acid (Isomer A). NMR #ppm(d6-DMSO): 2.00 (s, 3H), 3.43 (qAB, J=18Hz, 2H), 5.07(d, J=4Hz, 1H), 5.66 (dd, J=4Hz, J=8Hz, 1H), 6.40 (s, 1H), 7.07 (s, 1H), 9.50 (d, J=8Hz, 1H) (3) Using 7-[2-chlormethylene-2-(2-aminothiazol-4-yl)acetamido]desacetoxycephalosporanic acid (Isomer A), the reaction and purification were conducted following the procedures of 1 - (3) to obtain sodium 7-[2-chloro- methylene-2-(2-aminothiazol-4-yl)acetamido]desacetoxycephalosporanate (Isomer A). NMR #ppm (d6-DMSO): 1.90 (s, 3H), 3.20 (qAB, J=17Hz, 2H), 4.98 (d, J=4Hz, 1H), 5.54 (dd, J=4Hz, J=9Hz, lH), 6.44 (s, lH), 6.85 (s, lH), 7.15 (bs, 2H), 9.44 (d, J=8Hz, 1H) Elemental analysis for C14H12ClN4O4S2Na#2H2O: Calculated: C, 36.64; H, 3.51; N, 12.20 Found : C, 35.96; H, 3.24; N, 11.79 Example 3 (1) Using 2-chlormethylene-2-(2-formylaminothiazol-4 yl) acetic acid (Isomer A) and 7-amino-3-(1,3,4-thiadia zol-5-yl) thiomethyl-3-cephem-4-carboxylic acid as the starting materials, the reaction was carried out following the procedure of Example 1 - (1) to yield 7-[2chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]3-(1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A). NMR dppm(d6-DMSO): 3.69 Cm, 2H), 4.43 (qAB, J=13.5Hz, 2H), 5.16(d, J=6Hz, 1H), 5.79 (dd, J=6Hz, J=9Hz, 1H), 7.03 (s, 1H), 7.07 (s, 1H), 8.50 Cs, lH), 9.60 Cs, lH), 9.66 (d, J=9Hz, 1H) (2) Using 7-[2-chlormethylene-2-(2-formylaminothiazol4-yl)acetamido]-3-(1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (2) to yield 7-[2-chloromethylene 2-(2-aminothiazol-4-yl)acetamido]-3-tl,3,4-thiadiazol-5- yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A). This product was further subjected to the reaction and the purification following the procedures of 1 - (3) to obtain sodium 7-[2-chloromethylene-2-(2-aminothiazol-4 yl)acetamido]-3-(1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylate (Isomer A). NMR dppm(d6-DMSO): 3.50 (qAB, J=16Hz, 2H), 4.50 (qAB, J=12Hz, 2H), 5.06(d, J=4Hz, 1H), 5.62 (dd, J=4Hz, J=8Hz, 1H), 6.44 (s, 1H), 6.86 (s, 1H), 7.14 (bs, 2H), 9.48 (d, J=8Hz, 1H), 9.54 (s, 1H) Example 4 (1) Using 2-chlormethylene-2-(2-formylaminothiazol-4 yl)acetic acid (Isomer A) and 7-amino-3-(2,5-dihydro6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A) as the starting materials, the reaction was carried out following the procedure of Example 2 - (1) to yield 7-[2-chloromethylne2-(2-formylaminothiazol-4-yl)acetamido]-3-(2,5-dihydro6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A). NMR dppm(d6-DMSO): 3.50 (m, 3H), 3.60 (m, 2H), 4.23 (qAB, J=15Hz, 2H), 5.16(d, J=4Hz, 1H), 5.80 (dd, j=4Hz, J=9Hz, 1H), 7.03 (s, 1H), 7.06 (s, 1H), 8.53 Cs, 1H), 9.63 Cd, J=9Hz, 1H) (2) Using 7-[2-chlormethylene-2-(2-formylaminothiazol4-yl)acetamido]-3-(2,5-dihydro-6-hydroxy-2-methyl-5-oxoas-triazin-3-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (2) to yield 7-[2-chlormethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-astriazin-3-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A). NMR dppm(d6-DMSO): 3.63 (s, 3H), 3.75 (m, 2H), 4.26 ( (qAB, J=12Hz, 2H), 5.20(d, J=6Hz, 1H), 5.83 (dd, J=4.5Hz, J=7.5Hz, 1H), 6.43 (s, 1H), 6.89 (s, 1H), 9.63 (d, J=7.5Hz, 1H) (3) Using 7-[2-chlormethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-astriazin-3-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction and the purification were carried out following the procedures of Example 1 - (3) to obtain disodium 7-[2-chloromethylene 2-(2-aminothiazol-4-yl)acetamido]-3-(2,5-dihydro-6- hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thiomethyl-3cephem-4-carboxylate (Isomer A). NMR 8ppmCd6-DMSO): 3.48 (s, 3H), 3.58 (m, 2H), 4.32 J=12Hz, 2H), 5.06(d, J=4Hz, 1H), 5.60 (dd, J=4Hz, J=8Hz, 1H), 6.44 (s, lH), 6.86 (s, 1H), 7.20(bs, 2H), 9.48 (d, J=8Hz, lH) E Calculated: C, 33.21; H, 3.41; N, 13.06 Found : C, 33.77; H, 3.23; N, 14.07 Synthesis Example 2 (1) To DMF (3 ml) was added dropwise phosphorus oxychloride (1.18 g, 7.7 mmol) under ice-cooling. After the mixture was stirred at room temperature for 30 minutes, ethyl 2-formylphenylacetate (1.345 g, 7.0 mmol) was added dropwise to the mixture. After stirring at room temperature for 30 minutes, the mixture was heated at 1000C with stirring for 4 hours. Then, the temperature of the reaction mixture was returned to room temperature, and the reaction mixture was made to be alkaline by adding 1N aqueous sodium hydroxide solution. The mixture was extracted with ethyl acetate, and the extract was dried over magnesium sulfate. Evaporation of the solvent yielded an oily product of ethyl 2-chloromethylenephenylacetate (Isomer A : B = 3 : 7) (1.43 g, 82%). NMR dppm(CDCQ3): 1.26 (t, J=7Hz, 3H), 4.20 (q, J=7Hz, 2H), 6.53 (s, 0.3H), 7.10 # 7.37 (m, 5H), 7.50 (s, 0.7H). (2) Ethyl 2-chloromethylenephenylacetate (1.43 g, 6.3 mmol) (Isomer A : B = 3 : 7) was dissolved in THF (5 mQ), and to the mixture was added dropwise a solution of potassium hydroxide (1.06 g, 19 mmol) dissolved in water (10 mt). After the reaction mixture was stirred at room temperature for 24 hours, water (20 mQ) was added to the mixture, and the aqueous layer was washed with ether. Then, the aqueous layer was made acidic with 2N hydrochloric acid and extracted with ethyl acetate, and the extract was dried over magnesium sulfate. Concentration under reduced pressure yielded 2-chloromethylenephenylacetic acid (0.78 g, 65%) (Isomer A : B = 3 : 7) as crystals. NMR dppm(CDCQ3): 6.65 (s, 0.3H), 7.17 X 7.50 (m, 5H), 7.70 (s, 0.7H), 11.70 (bs, 1H). Example 5 (1) 2-Chloromethylenephenylacetic acid (Isomer A : B = 3 : 7, 0.44 g, 12.42 mmol) and 7-amino-3-tl-methyl-lH- tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (1.2 g, 2.42 mmol) were dissolved in methylene chloride (17 mQ). To the resultant solution was added N,N'-dicyclohexylcarbodiimide (0.55 g, 2.66 mmol), and the mixture was stirred at room temperature for 4 hours. The reaction mixture was subjected to filtration, and the filtrate was concentrated under reduced pressure to obtain an oily product. This product was separated and purified by column chromatography to yield 7-(2-chloromethylenephenylacetamido)-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester, (Isomer A, 0.16 g) and (Isomer B, 0.48 g), respectively. NMR dppm(CDCQ3) of Isomer A: 3.56 (qAB, J=15Hz, 2H), 3.73 Cs, 3H), 4.23 (qAB, J=1SHz, 2H), 4.89(d, J=4.5Hz, 1H), 5.83 (dd, J=4.5Hz, J=9Hz, 1H), 6.76 (d, J=9Hz, lH), 6.92 (s, 1H), 7.16 - 7.53(m, 5H, s, NMR #ppm (CDCl3) of Isomer B: : 3.56 (qAB, J=16.5Hz, 2H), 3.69 (s, 3H), 4.26 (qAB, J=13.5Hz, 2H), 4.92(d, J=4.5Hz, lH), 5.82 (dd, J=4.5Hz, J=9Hz, 1H), 6.39 (d, J=9Hz, 1H), 7.13 - 7.46(m, 5H), 7.56 (s, 1H) (2) 7-(2-Chlormethylenephenylacetamido)-3-(1-methyl1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A, 0.15 g, 0.22 mmol) was charged with anisole (0.2 ml), then with trifluoroacetic acid (0.9 ml) and the resultant mixture was stirred under ice-cooling for 1.5 hours. Under reduced pressure, the reaction mixture was concentrated. To the residue were added ethyl acetate (5 ml) and water (5 mQ) and the mixture was ice-cooled, followed by adjustment of pH to 8.30 with a saturated aqueous sodium hydrogen carbonate solution. After extraction, the aqueous layer was separated and extracted again with ethyl acetate (10 mt x 2). After separation of the aqueous layer, it was ice-cooled and adjusted to pH 2.0 with 2N-HCR. The precipitated crystals were collected by filtration, dried under reduced pressure over phosphorus pentoxide to yield 7 (2-chloromethylenephenylacetamido)-3-(1-methyl-lH-tetra- zol-5-yl) thiomethyl-3-cephem-4-carboxylic acid (Isomer A, 0.06 g) as white powders. NMR dppm(d6-DMSO): 3.70 (qAB, J=18Hz, 2H), 3.96 (s, 3H), 4.32 (qAB, J=12Hz, 2H), 5.08(d, J=4Hz, lH), 5.68 (dd, J=8Hz, 4Hz, lH), 7.32 (m, 6H), 9.10 (d, J=8Hz, 1H) Example 6 Using 7-(2-chloromethylenephenylacetamido)-3-(1-methyl-lH tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer B), the reaction was carried out following the procedure of Example 5 - (2) to yield 7-(2 chloromethylenephenylacetamido)-3-(l-methyl-la-tetrazol-5- yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer B). NMR dppm(d6-DMSO): 3.63 (qAB, J=18Hzt 2H), 3.89 Cs, 3H), 4.23 (qAB, J=15Hz, 2H), 5.07 (d, J=4.5Hz, 1H), 5.59 (dd, J=4.5Hz, J=7.5Hz, 1H), 7.16 (s, 1H), 7.33 (m, 5H), 9.10 (d, J=7.5Hz, 1H) Synthesis Example 3 (1) Ethyl formate (137 mt) was added dropwise to 10.6 g of 50% sodium hydride at room temperature under stirring over 35 minutes. After the dropwise addition, stirring was further continued for 10 minutes, followed by stirring at a bath temperature of 40 X 45 C for 20 minutes, and thereafter the temperature of the mixture was returned to room temperature. To this mixture, there was added ethyl (2-aminothiazol-5-yl)acetate in two divided por tions, and the resultant mixture was left to stand for 30 minutes. Then, under ice-cooling, 200 mQ of water was added to the mixture. After washing two times with ethyl acetate, the aqueous layer was combined and adjusted to pH 5.2 with 1N hydrochloric acid. The precipitated crystals were collected by fitration and dried to yield 14.66 g of pale brown crystals of ethyl 2-formyl-2-(2formylaminothiazol-5-yl)acetate. Ethyl 2-formyl-2-(2-formylaminothiazol-5-yl)acetate. IR (KBr): 1680, 1640, 1625 cm 1. NMR dppm(d6-DMSO): 1.30 Ct, J=7Hz, 3H), 4.25 (q, J=7Hz, 2H), 7.96(s, 1H), 8.02 (s, 1H), 8.51 (s, 1H) (2) Ethyl 2-formyl-2-(2-formylaminothiazol-5-yl)acetate (9.4 g) was added gradually under stirring to 27.9 g of ice-cooled phosphorus oxychloride, and the mixture was stirred at room temperature for 5 hours. Subsequently, 70 m± of benzene was added to the reaction mixture, and the precipitates were collected by filtration, washed with benzene and dried to yield 3.48 g of yellowish brown amorphous crystals of ethyl 2-chloro methylene-2-(2-formylaminothiazol-5-yl)acetate. The filtrate was washed with water, then with an aqueous sodium hydrogen carbonate solution, and dried to obtain 4.16 g of the same substance. Ethyl 2-chloromethylene-2- (2-formylaminothiazol-5-yl)- acetate: IR (KBr): 1705, 1680, 1660 cm 1 NMR dppm(d6-DMSO): 1.27 (t, J=7Hz, 3H), 4.25 (q, J=7Hz, 2H), 7.62 (s, 1H), 7.88 (s, 1H), 8.52 (s, 1H). (3) Ethyl 2-chloromethylene-2- (2-formylaminothiazol-5- yl)acetate (5.52 g) was dissolved in 55 mQ of water, and 55 mQ of water containing 4.18 g of potassium hydroxide was added dropwise over 20 minutes to the resultant solution at room temperature under stirring. After the dropwise addition, the mixture was adjusted to pH 8.0 and purified through HP-20 column. The purified product was adjusted to pH 3.8 with 1N hydrochloric acid, and the precipitated crystals were collected by filtration, washed with water and dried to yield 4.3 g of 2-chloromethylene-2-(2-formylaminothiazol-5-yl)acetic acid as yellow crystals. 2-Chloromethylene-2- (2-formylaminothiazol-5-yl) acetic acid: IR (KBr): 1690, 1665 cm-1 NMR dppm(d6-DMSO): 7.63 (s, lH), 7.95 (s, 1H), 8.52 (s, 1H). Example 7 (1) After 465 mg of 2-chloromethylene-2-(2-formylaminothiazol-5-yl)acetic acid and 988 mg of 7-amino-3-(1 methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester were suspended in 25 mt of THF, 494 mg of dicyclohexylcarbodiimide was added to the suspension and the mixture was stirred at room temperature for 2 hours. The precipitates were collected by filtration, charged with 30 mL of ethyl acetate, washed with water and dried over magnesium sulfate. Evaporation of the solvent yielded 1.34 g of 7-[2-chloromethylene-2 (2-formylaminothiazol-5-yl)acetamido]-3-(1-methyl-lHtetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester as crystals. 7-[2-Chlormethylene-2-(2-formylaminothiazol-5-yl) acetamido]- 3-( 1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester: IR (KBr): 1770, 1705, 1680, 1630 cm NMR dppm(d6-DMSO): 3.88 (s, 3H), 5.22 (d, J=5Hz, lH), 5.80 (dd, J=5Hz, 7Hz, 1H), 6.90 (s, lH), 6.99 (s, 1H), 7.36 (bs, 10H), 7.79 (s, lH), 8.53 (s, 1H), 9.61 (d, J=7Hz, 1H). (2) To a suspension of 1 g of 7-[2-chloromethylene-2 (2- formylaminothiazol- 5-yl) acetamido] -3- (l-methyl-lH- tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester in 20 mQ of methanol, there was added under ice-cooling 0.5 m± of phosphorus oxychloride. After the mixture was stirred under ice-cooling for 2 hours and at room temperature for 2 hours, ethyl acetate was added to the reaction mixture. The mixture was then washed successively with water, a saturated aqueous sodium hydrogen carbonate solution and water, followed by drying over magnesium sulfate. Evaporation of the solvent yielded 1.02 g of 7-[2-chloromethylene-2-(2-aminothiazol-5-yl)- acetamidol-3-tl-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester as pale yellow amorphous crystals. 7-[2-Chloromethylene-2-(2-aminothiazol-5-yl)acetamido] 3- C1-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester: IR (KBr): 1790, 1720, 1670, 1620 cm . (3) 7- [2-Chloromethylene-2- (2-aminothiazol-5-yl) acetamido] -3- (l-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem4-carboxylic acid benzhydryl ester (514 mg) was suspended in 1 mi of methylene chloride, and to the resultant suspension, under ice-cooling, there were added 0.5 mQ of anisole and 1 mQ of trifluoroacetic acid. After 30 minutes, water was added to the reaction mixture and pH of the mixture was adjusted to 7 with a saturated aqueous sodium hydrogen carbonate solution, followed by washing with ethyl acetate. The aqueous layer was separated and adjusted to pH 3.2 with 1N hydrochloric acid. The precipitated crystals were collected by filtration, washed with water and dried to yield 140 mg of crystals of 7-[2-chloromethylene-2-(2-aminothiazol-5 yl)acetamido]-3-(1-methyl-1H.-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid. 7-t2-Chloromethylene-2-(2-aminothiazol-5-yl)acetamido]- 3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4- carboxylic acid: NMR 6ppm(d6-DMSO): 3.92 (s, 3H), 4.30 (qAB, J=13Hz, 2H), 5.10 (d, J=4Hz, 1H), 5.63 (dd, J=4Hz, 8Hz, 1H), 6.50 (s, 1H), 7.24 (s, 1H), 7.35 (bs, 2H), 9.49 (d, J=8Hz, 1H). (4) 7-[2-Chloromethylene-2-(2-aminothiazol-5-yl)acet- amido] -3- Cl-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem- 4-carboxylic acid (106 mg) was dissolved in a solution of 2 mQ of water and 16.3 mg of sodium hydrogen carbonate, and the mixture was stirred with addition of activated charcol. After filtration with a membrane filter, lyophilization of the product yielded sodium 7 [2-chloromethylene-2-(2-aminothiazol-5-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate (decomposition point: 155 X 158 C). Sodium 7-[2-chlormethylene-2-(2-aminothiazol-5-yl) acetamido] -3- (1-methyl-lH-tetrazol-S-yl) thiomethyl-3- cephem-4-carboxylate: IR (KBr): 1760, 1660, 1605 cm . Example 8 (1) 2-Chloromethylene-2- (2-formylaminothiazol-5-yl)acetic acid (2.50 g) and 7-aminocephalosporanic acid benzhydryl ester (4.38 g) were dissolved in 250 ml of ethyl acetate and 80 mQ of THF. Then, 3.0 g of dicyclohexylcarbodiimide was added to the resultant solution at room temperature, and the mixture was stirred at the same temperature for 2 hours. The precipitates were removed by filtration and the filtrate was washed with a saturated aqueous sodium hydrogen carbonate solution, then with water, followed by concentration. The precipitated crystals were collected by filtration, washed with ethyl acetate and dried to yield 5.13 g of 7-[2chloromethylene-2-(2-formylaminothiazol-5-yl)acetamido]cephalosporanic acid benzhydryl ester as brown crystals. 7-[2-Chloromethylene-2-(2-formylaminothiazol-5-yl)acet amidolcephalosporanic acid benzhydryl ester: NMR dppm(d6-DMSO): 1.98 (s, 3H), 3.62 (bs, 2H), 4.80 J=13Hz, 2H), 5.23 (d, J=4Hz, 1H), 5.80 (dd, J=4Hz, 8Hz, lH), 6.92 (s, 1E), 7.35 (m, 10H), 7.78 (s, 1H), 8.50 (s, 1B), 9.56 (d, J=8Hz, 1H). (2) 7-[2-Chloromethylene-2-(2-formylaminothiazol-5-yl)- acetamido]cephalosporanic acid benzhydryl ester (2.0 g) was dissolved in 4 mQ of methylene chloride. Then, 1.0 mQ of anisole was added to the resultant solution and 20 mQ of trifluoroacetic acid was added under ice-cooling, followed by stirring at room temperature for 3 hours. After concentration of the solvent, ethyl acetate was added to the residue. The precipitates were collected by filtration, washed with ethyl acetate and dried to yield 1.08 g of 7-[2-chloromethylene-2-(2-formylaminothiazol-5- yl)acetamido]cephalosporanic acid as yellow amorphous crystals. 7-[2-Chloromethylene-2-(2-formylaminothiazol-5-yl)acet- amido] cephalosporanic acid: NMR dppm(d6-DMSO): 2.03 (s, 3H), 3.57 (bs, 2H), 4.87 (qAB, J=13Hz, 2H), 5.18 (d, J=4Hz, 1H), 5.74 (dd, J=4Hz, 8Hz, 1H), 6.97 (s, 1H), 7.78 (s, 1H), 8.50 (s, 1H), 9.55 (d, J=8Hz, 1H). (3) 7- [2-Chloromethylene- 2- ( 2-formylaminothiazol- 5-yl) - acetamido]cephalosporanic acid (1.20 g) was suspended in 20 mQ of methanol, and under ice-cooling 0.19 g of phosphorus oxychloride was added to the suspension. Then, the mixture was stirred at room temperature for 6 hours. After the reaction was over, 10 ml of water was added and pH of the mixture was adjusted to 5.0 with a saturated aqueous sodium hydrogen carbonate solution. After evaporation of methanol, the residue was adjusted to pH 7.5 and then washed for 4 times with ethyl acetate. Insolubles were removed by filtration and the filtrate was adjusted to pH 2.5 with IN hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to yield 0.46 g of 7-[2-chloromethylene-2-(2-aminothiazol-5-yl) acetamido] cephalosporanic acid as yellow amorphous crystals (decomposition point: 157 X 160 C). 7-t2-Chloromethylene-2-(2-aminothiazol-5-yl)acetamido]- cephalosporanic acid: IR (KBr): 1775, 1735, 1660, 1630 cm 1 NMR dppm(d6-DMSO): 2.03 (s, 3H), 3.57 (bs, 2H), 4.85 - J=13Hz, 2H), 5.14 (d, J=4Hz, 1H), 5.67 (dd, J=4Hz, 8Hz, 1H), 6.53 (s, lH), 7.28 (s, 1H), 9.44 (d, J=8Hz, 1H). (4) 7-[2-Chlormethylene-2-(2-aminothiazol-5-yl)acetamido]cephalosporanic acid (100 mg) was dissolved in a solution of 2 mQ of water and 16.5 mg of sodium hydrogen carbonate, and the mixture was stirred with addition of activated charcoal. After filtration with a membrane filter, lyophilization of the product yielded sodium 7 [2-chloromethylene-2-(2-aminothiazol-5-yl)acetamido]- cephalosporanate as yellow amorphous crystals. Sodium 7-[2-chloromethylene-2-(2-aminothiazol-5-yl)- acetamido]cephalosporanate: IR (KBr): 1760, 1730, 1640, 1600 cm 1. Synthesis Example 4 (1) 2-Formylamino-5-thiocyanothiazol (925 mg) was suspended in 20 mQ of absolute ethanol, and under icecooling 204 mg of sodium borohydride was gradually added to the suspension. Then, the temperature of the mixture was returned to room temperature and then the mixture was ref fluxed further for 10 minutes. After cooling, 6 mt of absolute ethanol containing 337 mg of 85% potassium hydroxide was added to the mixture, and the mixture was stirred at room temperature for 1 to 2 minutes. After dropwise addition of 2.5 mQ of absolute ethanol containing 918.5 mg of ethyl bromoacetate, the resulting mixture was stirred at room temperature for 1 hour. Thereafter, water was added to the reaction mixture and pH of the mixture was adjusted to 6.6 with 1N hydrochloric acid, followed by evaporation of the solvent under reduced pressure. The precipitated crystals were collected by filtration, washed and dried to obtain 950 mg of ethyl 3- (2-formylaminothiazol-5-yl)mercaptoacetate as colorless crystals. Ethyl 3- (2-formylaminothiazol-5-yl)mercaptoacetate: -l IR (KBr): 3190, 1730, 1680 cm NMR #ppm (CDCl3): 1.27 (t, 3H), 3.48 (s, 1H), 4.19 (q, 1H), 7.52 (s, 1H), 8.61 (s, 1H), 12.2 (bs, 1H). (2) To 288 mg of 50% sodium hydride was gradually added dropwise 5 mQ of ethyl formate at room temperature under stirring. After the dropwise addition, the reaction was completed by heating the mixture at about 450C. After cooling, 492 mg of 3-(2-formylaminothiazol-5-yl)mercaptoacetic acid was added all at once to the mixture, and the mixture was stirred at room temperature for 1 hour. Then, 10 mQ of water and 5 mQ of ethyl acetate were added to the reaction mixture and the reaction mixture was separated. The aqueous layer was separated, and the ethyl acetate layer was washed with 2 mQ of water. The aqueous layer and washings were combined and adjusted to pH 3.5 with 1N hydrochloric acid. The aqueous layer was extracted with ethyl acetate, and the extract was washed successively with water and a saturated aqueous sodium hydrogen carbonate solution, followed by drying over magnesium sulfate. Evaporation of the solvent yielded 450 mg of ethyl 2-formyl-3-(2-formylaminothiazol-5-yl)mercaptoacetate as pale yellow crystals. Ethyl 2-formyl-3-(2-formylaminothiazol-5-yl)mercaptoacetate: IR (KBr): 3190, 1685, 1640 cm 1. NMR dppmEd6-DMSO): 1.22 (t, 3H), 4.11 (q, 2H), 7.45 (s, 1H), 8.08 (s, 1H), 8.46 (s, 1H). (3) Phosphorus oxychloride (10.96 mQ) was added to 2.74 g of ethyl 2-formyl-3-(2-formylaminothiazol-5-yl)mercaptoacetate, and the mixture was stirred at room temperature for 12 to 16 hours. Then, ethyl acetate was added to the mixture, and the mixture was washed with a 5% aqueous sodium hydrogen carbonate solution until the washings became alkaline. Subsequently, the reaction mixture was washed with water and then with a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent yielded 2.59 g of ethyl 2 chloromethylene-3- (2-formylaminothiazol-5-yl) mercapto- acetate as pale yellow crystals. Ethyl 2-chlormethylene-3-(2-formylaminogthiazol-5-yl)mercaptoacetate: IR (KBr): 1700 cm NMR dppm(d6-DMSO): 1.17 (t, 3H), 4.08 (q, 2H), 7.60 (s, 1H), 7.76 (s, 1H), 8.49 (s, 1H). (4) Ethyl 2-chlormethylene-3-(2-formylaminogthiazol-5yl)mercaptoacetate (1.3 g) was suspended in 10 mQ of water, and 20 mQ of water containing 880 mg of 85% potassium hydroxide was added dropwise to the suspension at room temperature under stirring. Stirring was continued at room temperature for 15 minutes. Then, the reaction mixture was adjusted to pH 8.8 with 1N hydrochloric acid and washed with ethyl acetate. Then, the ethyl acetate in the aqueous layer was removed by distillation under reduced pressure. The reaction mixture was adjusted to pH 2.0 with 1N hydrochloric acid, and stirred under ice-cooling for 1 hour. The precipitated crystals were collected by filtration, washed with water and dried to obtain 850 mg of 2-chloromethylene-3-(2-formylaminothiazol-5-yl)mercaptoacetic acid as pale yellow crystals. 2-Chloromethylene-3-(2-formylaminothiazol-5-yl)mercapto- acetic acid: IR (KBr): 1690, 1660 cm 1. NMR dppm(d6-DMSO): 7.59 (s, lH), 7.72 (s, lH), 8.49 (s, 1H). Example 9 (1) After 842 mg of 2-chloromethylene-3-(2-formylamino- thiazol-5-yl)mercaptoacetic acid and 1.43 g of 7-amino 3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester were suspended in 30 mQ of THF, 715 mg of dicyclohexylcarbodiimido was added to the suspension and the mixture was stirred at room temperature for 2.5 hours. The precipitates were removed by filtration, and the THF was removed by distillation. Then, after ethyl acetate was added to the residue, the precipitates were removed again by filtration. Then, the filtrate was washed successively with a saturated aqueous sodium hydrogen carbonate solution, water and a saturated saline solution, followed by drying over magnesium sulfate. Concentration under reduced pressure followed by purification by column chromatography yielded 1.59 g of 7-t2-chloromethylene-3-(2-formylaminothiazol-5-yl)- mercaptoacetamido]-3-(1-methyl-lH-tetrazol-5-yl)thio- methyl-3-cephem-4-carboxylic acid benzhydryl ester as yellow amorphous crystals. 7-[2-Chloromethylene-3-(2-formylaminothiazol-5-yl)mer captoacetSmido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid benzhydryl ester: NMR dppm(CDCQ3): 3.72 (bs, SH), 4.25 (bs, 2H), 4.92 (d, 1H), 5.77 (q, 1H), 6.89 (s, 1H), 7.29 (bs, 10H), 7.57 (s, 1H), 7.60 (s, 1H), 7.85 (d, 1H), 8.42 (s, 1H). (2) 7-[2-Chloromethylene-3-(2-formylaminothiazol-5-yl) mercaptoacetamido]-3-(1-methyl-lH-tetrazol-5-yl)thio- methyl-3-cephem-4-carboxylic acid benzhydryl ester (370 mg) was dissolved in 2.5 mQ of anhydrous methylene chloride. Then, 0.75 mZ of anisole was added to the solution, and under ice-cooling, 1.5 mQ of trifluoroacetic acid was added to the mixture. The resulting mixture was stirred at the same temperature for 2 hours. To the reaction mixture was added 20 mt of ethyl acetate, and the mixture was washed twice with water and extracted twice with a 5% aqueous sodium hydrogen carbonate solution. The extract was adjusted to pH 1.5 with 1N hydrochloric acid and extracted with ethyl acetate. The resulting extract was washed successively with water and a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent yielded 238 mg of 7-[2-chloromethylene-3-(2-formylaminothiazol-5-yl)mercaptoacet amido] -3- C l-methyl-lH-tetrazol- S-yl) thiomethyl- 3-cephem- 4-carboxylic acid as pale yellow crystals. 7-[2-Chloromethylene-3-(2-formylaminothiazol-5-yl)mer- captoacetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl3-cephem-4-carboxylic acid: NMR dppm(d6-DMSO): 3.56 (d, 1H), 3.73 (d, 1H), 3.95 (s, 3H), 4.26 (d, 1H), 4.38 (d, 1H), 5.04 (d, 1H), 5.55 (dd, 1H), 7.22 (s, 1H), 7.63 (s, 1H), 9.44 (s, 1H). (3) Phosphorus oxychloride (666 mg) was added to 8 mQ of absolute methanol under ice-cooling. After the mixture was stirred for 5 minutes, 500 mg of 7-12- chloromethylene-3- (2-formylaminothiazol-S-yl)mercapto- acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid was added thereto, and the resulting mixture was stirred at room temperature further for 1 hour. Then, 8 mQ of water was added to the mixture under ice-cooling, and the resulting mixture was adjusted to pH 3.0 with a 10% aqueous sodium hydroxide solution. Subsequently, the reaction mixture was stirred under icecooling for 6 hours, and left to stand in a refrigerator for 16 hours. The precipitated crystals were collected by filtration, followed by washing and drying to obtain 330 mg of 7-[2-chloromethylene-3-(2-aminothiazol-5-yl)- mercaptoacet2mido]-3-(l-methyl-lH-tetrazol-5-yl)thi methyl-3-cephem-4-carboxylic acid as pale yellow crystals. 7-[2-Chloromethylene-3-(2-aminothiazol-5-yl)mercaptoacetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem4-carboxylic acid: IR (KBr): 1770, 1710, 1660, 1620 cm 1. NMR dppm(d6-DMSO): 3.68 (bs, 2H), 3.95 (s, 3H), 4.25 (d, 1H), 4.39 (d, 1H), 5.03 (d, J=S.OHz, 1H), 5.58 (dd, J=8.0, 5.0 Hz, 1H), 7.13 (s, 1H), 7.17 (s, 1H), 7.65 (bs, 2H), 9.39 (d, J=8.0Hz, 1H). (4) 7-[2-Chlormethylene-2-(2-aminothiazol-5-yl)mercaptoacetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl3-cephem-4-carboxylic acid (115.9 mg) was dissolved in a solution composed of 2 ml of water and 16.8 mg of sodiumhydrogen carbonate, activated charcoal was added to the solution, and the mixture was stirred. After filtration of the mixture through a membrane filter, the filtrate was lyophilized to afford 110 mg of sodium 7-[2-chloromethylene-3-(2-aminothiazol-5-yl)mercaptoacetamido]-3 (1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylate as pale yellow crystals (decomposition point: 165 X 1700C). Synthesis Example 5 To a mixture of 44 mQ of ethanol and 146 ml of water, there were added 5.5 g of 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetic acid, 2.2 g of ethyl mercaptan and 2.79 g of sodium hydroxide, and the mixture was stirred at room temperature for 4.5 hours. The reaction mixture was then washed with ethyl acetate, and adjusted to pH 4.5 with 1N hydrochloric acid. The precipitated stals were collected by filtration, washed with water 1 dried to obtain 4.4 g of 2-ethylmercaptomethylene-2- -formylaminothiazol-4-yl)acetic acid as yellow crystals. '-Ethylmercaptomethylene-2-(2-formylaminothiazol-4-yl)- acetic acid: NMR dppm(d6-DMSO): 1.28 (t, J=7Hz, 3H), 2.88 (q, J=7Hz, 2H), 7.42 (s, 1H), 7.89 (s, 1H), 8.47 (s, 1H). Example 10 (1) After 2.52 g of 2-ethylmercaptomethylene-2-(2formylaminothiazol-4-yl)acetic acid and 4.5 g of 7-amino 3- (1-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester were dissolved in 160 mt of THF, 2.72 g of dicyclohexylcarbodiimido was added to the solution, and the mixture was stirred at room temperature for 25 hours. After the precipitates were removed by filtration, the filtrate was evaporated to dryness under reduced pressure. The residue was washed with ethyl acetate and dried to obtain 4.35 g of 7-t2- ethylmercaptomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-ylithiomethyl-3cephem-4-carboxylic acid benzhydryl ester as brown amorphous crystals. 7-[2-Ethylmercaptomethylene-2-(2-formylaminothiazol-4yl)acetamido]-3-(l-methyl-lH-tetrazol-5-yl)thiomethyl-3 cephem-4-carboxylic acid benzhydryl ester: NMR dppm(d6-DMSO): 1.27 (t, J=7Hz, 3H), 2.89 (q, J=7Hz, 2H), 3.77 (bs, 2H), 3.87 (s, 3H), 4.27 J=13Hz, 2H), 5.15 (d, J=4Hz, lH), 5.90 (dd, J=4Hz, 8Hz, 1H), 6.89 (s, 1H), 7.25 (s, 1H), 7.32 (m, 10H), 7.62 (s, 1H), 8.46 (s, 1H), 9.09 (d, J=8Hz, 1H). (2) 7- [2-Ethy lmercaptomethylene- 2- (2- formylaminothiazol 4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid benzhydryl ester (2.0 g) was dissolved in 10 mt of methylene chloride. Then, 0.88 g of anisole was added to the solution, and 2.6 g of trifluoroacetic acid was added dropwise thereto under icecooling, followed by stirring at the same temperature for 3 hours. After evaporation of the solvent from the reaction mixture, benzene was added to the residue. The mixture was adjusted to pH 7.5 with an aqueous sodium hydrogen carbonate solution, and washed with benzene and ethyl acetate, successively. After the mixture was adjusted to pH 5.6 with IN hydrochloric acid and the precipitates were removed by filtration, the filtrate was adjusted to pH 3.5. Resulting precipitates were removed by filtration, and the filtrate was washed with water and dried to obtain 0.76 g of 7-[2-ethylmercaptomethylene2-(2-formylaminothiazol-4-yl)acetamido]-3-(1-methyl-lH tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as yellow amorphous crystals. 7-12-Ethylmercàptomethylene-2-(2-formylaminothiazol-4- yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid: NMR dppmEd6-DMSO): 1.29 Ct, J=7Hz, 3H), 2.92 (q, J=7Hz, 2H), 3.70 (bs, 2H), 3.95 (s, 3H), 4.33 (bs, 2H), 5.10 (d, J=4Hz, 1H), 5.86 (dd, J=4Hz, 8Hz, 1H), 7.25 (s, 1H), 7.61 (s, 1H), 8.48 (s, 1H), 9.05 (d, J=8Hz, 1H). (3) To a mixed solution composed of 7 mt of THF, 14 mt of methanol and 0.94 g of phosphorus oxychloride, there was added 0.7 g of 7-[2-ethylmercaptomethylene-2-(2 formylaminothiazol-4-y1) acetamido] -3- (l-methyl-lH-tetra- zol-5-yl)thiomethyl-3-cephem-4-carboxylic acid under icecooling. Then, the resulting mixture was stirred at the same temperature for 2 hours. After 50 mt of water was added thereto, the mixture was adjusted to pH 3.5 with an aqueous sodium hydrogen carbonate solution, followed by evaporating methanol from the mixture. Then, the residue was adjusted to pH 7.5, washed with ethyl acetate, and adjusted to pH 3.5 with 1N hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to obtain 0.4 g of 7-[2-ethylmercaptomethylene- 2- (2- aminothiazol- 4-yl) acetamido] - 3- (1-methyl- lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as yellow amorphous crystals (decomposition point: 146 a 1480C). 7-t2-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl)- acetamidol-3-(1-methyl-lH-tetrazol-5-yl)thicmethyl-3- cephem-4-carboxylic acid: IR (KBr): 1770, 1710, 1620 cm 1. NMR dppm(d6-DMSO): 1.27 (t, J=7Hz, 3H), 2.90 (q, J=7Hz, 2H), 3.70 (bs, 2H), 3.94 (s, 3H), 4.33 (qAB, J=13Hz, 2H), 5.10 (d, J=4Hz, 1H), 5.82 (dd, J=4Hz, 8Hz, 1H), 6.60 (s, 1H), 7.08 (bs, 2H), 7.65 (s, 1H), 9.75 (d, J=8Hz, 1H). (4) 7- (2-Ethylmercaptomethylene-2- (2-aminothiazol-4-yl)- acetamido]-3-(l-methyl-lH-tetrazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (100 mg) was dissolved in a solution composed of 2 mt of water and 14 mg of sodium hydrogen carbonate. To the solution was added activated charcol, and the mixture was stirred and filtrated through membrane filter. Then, the filtrate was lyophilized to obtain sodium 7-[2-ethylmercaptomethylene-2-(2- aminothiazol- 4-yl) acetamido] -3- (1-methyl- lH- tetrazol- S- yl)thiomethyl-3-cephem-4-carboxylate as yellow amorphous crystals. Synthesis Example 6 To a mixed solution composed of 24 mt of water, 4.28 g of ethyl mercaptan and 3.87 g of sodium hydroxide, there were added 6.0 g of ethyl 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetate dissolved in 48 mQ of ethanol. After the solution was stirred under refluxing for 2.5 hours, 200 mL of water was added thereto. Then, the mixture was washed with ethyl acetate, followed by adjusting to pH 4.2 with 1N hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to obtain 3.33 g of 2-ethylmercaptomethylene2-(2-aminothiazol-4-yl)acetic acid (Isomer A and B) asyellow amorphous crystals. 2-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl)acetic acid (Isomer A and B): NMR dppm(d6-DMSO): 1.28 (t, J=7Hz, 3H), 2.78 (q, J=7Hz, 2H), 2.85 (q, J=7Hz, 2H), 6.74 Cs, 1H), 6.78 (s, 1H), 7.02 (bs, 2H), 7.18 (bs, 2H), 7.82 (s, 1H), 7.90 (s, 1H). Example 11 (1) After 0.8 g of 2-ethylmercaptomethylene-2-(2aminothiazol-4-yl)acetic acid (Isomer A and B) and 1.61 g of 7-amlno-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester were dissolved in 120 m & of THF, 0.97 g of dicyclohexylcarbodiimido was added to the solution at 250C. Then, the resulting mixture was stirred at the same temperature for 47 hours. The precipitates were removed by filtration, and the filtrate was concentrated under reduced pressure. The precipitates were collected by filtration, washed successively with ethyl acetate and methylene chloride, and dried to obtain 0.28 g of 7-[2-ethylmercaptomethylene-2 (2-aminothiazol-4-yl) acetamido] -3- (1-methyl-lH-tetrazol- 5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A and B) as yellow amorphous crystals. 7-E2-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester (Isomer A and B): NMR dppm(d6-DMSO): 1.26 (t, J=7Hz, 3H), 2.80 (q, J=7Hz, 2H), 3.78 (bs, 2H), 3.88 (s, 3H), 4.30 J=13Hz, 2H), 5.19 (d, J=4Hz, lH), 5.96 (dd, J=4Hz, 8Hz, 1H), 6.52 (s, 1H), 6.90 (s, lH), 7.07 (bs, 1H), 7.38 (m, 10H), 7.56 (s, 1H), 7.68 (s, lH), 9,64 (d, J=8Hz, 1H). (2) 7-[2-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester (0.23 g, Isomer A and B) was dissolved in 3 mQ of methylene chloride. After 0.11 g of anisole was added to the solution, 0.31 g of trifluoroacetic acid was added dropwise thereto under ice-cooling, and the mixture was stirred at the same temperature for further 2.5 hours. After evaporation of the solvent, the residue was adjusted to pH 7.5 with an aqueous sodium hydrogen carbonate solution, washed 3 times with ethyl acetate, and then adjusted to pH 3.6 with 1N hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to obtain 0.05 g of 7-[2-ethylmercaptomethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid (Isomer A and B) as yellow amorphous crystals. 7-12-Ethylmercaptomethylene-2-(2-aminothiazol-4-yl)acet- amido] - 3- (1-methyl- lH-tetrazol- 5-yl) thiomethy 1- 3-cephem4-carboxylic acid (Isomer A and B): NMR dppm(d6-DMSO): 1.25 Ct, 7Hz, 3H), 2.78 (q, J=7Hz, 2H), 3.72 (bs, 2H), 3.94 (s, 3H), 5.12 (d, J=4Hz, lH), 5.88 (dd, J=4Hz, 8Hz, 1H), 6.51 (s, 1H), 7.07 (bs, 2H), 7.24 (s, 1H), 9.58 (d, J=8Hz, 1H). Synthesis Example 7 After 0.75 g of sodium hydroxide was added to 25 g of 15% aqueous methyl mercaptan solution, the resulting mixture was added 4.65 g of ethyl 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetate dissolved in 37 mt of ethanol. After the reaction mixture was stirred under ref fluxing for 3 hours, 150 mL of water was added thereto. Then, the mixture was washed with ethyl acetate and adjusted to pH 4.8 with 1N hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to obtain 1.87 g of 2-methylmercaptomethylene-2-(2-amino- thiazol-4-yl)acetic acid (Isomer A and B) as yellow amorphous crystals. 2-Methylmercaptomethylene-2- (2-aminothiazol-4-yl) aceitic acid (Isomer A and B): NMR dppm(d6-DMSO): 2.38 (s, 3H), 2.48 (s, 3H), 6.77 (s, 1H), 6.82 (s, 1H), 7.05 (bs, 2H), 7.19 (bs, 2H), 7.80 (s, 1H), 7.92 (s, 1H). Example 12 (1) After 1.5 g of 2-methylmercaptomethylene-2-(2-amino- thiazol-4-yl)acetic acid (Isomer A and B) and 3.2 g of 7 amino- 3- Ci-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester were dissolved in 240 mi of THF, 1.94 g of dicyclohexylcarbodiimido was added thereto. Then, the mixture was stirred at the temperature of 22 # 290C for 67 hours. After the precipitates were removed by filtration, filtrate was concentrated under reduced pressure. The precipitates were collected by filtration, washed successively with ethyl acetate and methylene chloride, and dried to obtain 1.92 g of 7-[2-methylmercaptomethylene-2-(2-aminothiazol-4- yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester (Isomer A and B) as brown crystals. 7-[2-Methylmercaptomethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester (Isomer A and B): NMR dppm(d6-DMSO): 2.34 (s, 3H), 2.45 (s, 3H), 3.78 (bs, 2H), 3.86 (s, 3H), 4.30 (qAB, J=13Hz, 2H), 5.16 (d, J=4Hz, lH), 5.90 (dd, J=4Hz, 8Hz, lH), 6.50 (s, 1H), 6.60 (s, lH) , 6.87 (s, 1H), 7.05 (bs, 2H), 7.32 (m, 10H), 7.58 (s, 1H), 9.62 (d, J=8Hz, 1H), 9.78 (d, J=8Hz, 1H). (2) 7-[3-Methylmercaptomethylene-2-(2-aminothiazol-4 yl)acetamido]¯3¯(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-l-carboxylic acid benzhydryl ester (1.5 g, Isomer A and B) was dissolved in 10 mt of methylene chloride. After 0.7 g of anisole was added thereto, 2.07 g of trifluoroacetic acid was added dropwise to the mixture under ice-cooling. Then, the mixture was stirred at room temperature for 2.5 hours. After evaporation of the solvent, the residue was adjusted to pH 7.2 with an aqueous sodium hydrogen carbonate solution, washed with ethyl acetate, and adjusted to pH 3.5 with 1N hydrochloric acid. The precipitates were collected by filtration, washed with water and dried to obtain 0.48 g of 7-[2-methylmercapto methylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-methyl- lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A and B) as yellow amorohous crystals. 7-t2-Methylmercaptomethylene-2-(2-aminothiazol-4-yl)- acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid (Isomer A dnd B): NMR dppm(d6-DMSO): 2.35 (s, 3H), 2.47 (s, 3H), 3.70 (bs, 2H), 3.94 (s, 3H), 5.10 (d, J=4Hz, 1H), 5.78 (m, 1H), 6.52 (s, 1H), 6.61 (s, 1H), 7.10 (bs, 2H), 7.23 (bs, 2H), 7.35 (s, 1H), 7.61 (s, 1H). Synthesis Example 8 (1) After 2.14 g of ethyl (2-formylaminothiazol-4-yl)- acetate was dissolved in 50 mQ of 1,4-dioxane, 2.22 g of selenium dioxide was added thereto, and the mixture was ref fluxed for 2 hours. The thermotime reaction mixture was collected by filtration and the filtrate was left to stand over night. The precipitated crystals were collected by filtration, washed with ethyl acetate and dried to obtain 2.12 g of ethyl (2-formylaminothiazol-4yl)glyoxalate as colorless crystals. Ethyl (2-formylaminothiazol-4-yl)glyoxalate: IR (KBr): 1730, 1680 cm-1 NMR #ppm(d6-DMSO): 1.35 (t, J=7Hz, 3H), 4.38 (q, J=7Hz, 2H), 8.52 (s, 1H), 8.59 Cs, 1H), 12.7 (bs, 1H). (2) After 1.7 g of ethyl (2-formylaminothiazol-4-yl)glyoxalate was suspended in 35 mt of THF, 2.7 g of cyanomethylenetriphenylphosphorane was added to the suspension. Subsequently, the mixture was stirred at room temperature for 4 hours, and the reaction mixture was concentrated. After the concentrate was passed through the silica gel column chromatography, the resulting eluate was concentrated to obtain ethyl 2-cyanomethylene-2-(2formylaminothiazol-4-yl)acetate (Isomer A and B). Ethy 2-cyanomethylene-2-(2-formylaminothiazol-4-yl)acetate: Isomer A: NMR #ppm(d6-DMSO): 1.33 (t, 3H), 4.32 (q, 2H), 6.59 (s, lH), 7.84 (s, 1H), 8.56 (s, 1H), 12.4 cubs, 1H). Isomer B: NMR #ppm(d6-DMSO): 1.38 (t, 3H), 4.43 (q, 2H), 6.65 Cs, 1R), 7.76 (s, 1H), 8.56 (s, 1H), 12.4 (bs, 1H). (3) To the aforementioned ethyl 2-cyanomethylene-2-(2 formylaminothiazol-4-yl)acetate (Isomer A and B) was added 28 mQ of 3% aqueous potassium hydroxide solution, and the resulting mixture was stirred at room temperature for 1 hour. The insolubles were removed by filtration and the filtrate was washed with ethyl acetate. The residue was adjusted to pH 3.0 with 1N hydrochloric acid and extracted twice with ethyl acetate. The extract was washed twice with water and then washed twice with a saturated saline solution, and dried over magnesium sulfate. The resulting solution was concentrated and the precipitates were collected by filtration to obtain 1.42 g of 2-cyanomethylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A and B) as yellow amorphous crystals. 2-Cyanomethylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A and B): IR (KBr): 2210, 1720, 1690, 1640 cm Example 13 (1) After 1.42 g of 2-cyanomethylene-2-(2-formylaminothiazol-4-yl)acetic acid and 2.62 g of 7-amino-3-(1methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester were suspended in 50 mQ of THF, 1.42 g of dicyclohexylcarbodiimido was added to the suspension. Subsequently, the mixture was stirred at room temperature for over night. After the mixture was filtrated, the filtrates were concentrated. The residue was passed through column chromatography to obtain 1.24 g of pale yellow crystals (Isomer A) and 1.41 g of pale yellow amorphous crystals (Isomer B) of 7-[2-cyano methylene-2- (2-formylaminothiazol-4-yl) acetamido] -3-Cl- methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester, respectively. 7-[2-Cyanomethylene-2-(2-formylaminothiazol-4-yl)acet amido] -3- C1-methyl-lH-tetrazol-S-yl) thiomethyl-3-cephem- 4-carboxylic acid benzhydryl ester: Isomer A: IR (KBr): 2210, 1770, 1715, 1698, 1680 cm-1. NMR #ppm(d6-DMSO): 3.80 (bs, 2H), 3.89 (s, 3H), 4.33 (bs, 2H), 5.25 (d, J=5Hz, 1H), 5.90 (dd, J=8Hz, 5Hz, 1H), 6.16 (s, w 6.94 (s, 1H), 7.40 (m, ION), 7.73 (s, 1H), 8.56 (s, 1H), 9.72 (d, J=8Hz, 1H), 12.5 (bs, 1H). Isomer B: IR (KBr): 2210, 1780, 1715, 1675 cm NMR #ppm(d6-DMSO): 3.79 (bs, 2H), 3.87 87 (s, 3H), 4.31 cubs, 2H), 5.29 (d, J=5Hz, 1H), 5.96 (dd, J=8Hz, 5Hz, 1H), 6.37 (s, 1H), 6.91 (s, 1H), 7.38 (m, 10H), 7.51 (s, 1H), 8.54 (s, 1H), 9.97 (d, J=8Hz, 1H), 12.5 (bs, 1H). (2) To a mixed solution composed of 1.67 ml of trifuloroacetic acid, 0.84 g of anisole and 2.8 mQ of anhydrous methylene chloride, there was added 390 mg of 7-[2-cyanomethylene-2-(2-ormylaminothiazol-4-yl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester (Isomer B) under icecooling. Then, the resulting mixture was stirred for 50 minutes. After 50 mL of ethyl acetate and 20 mL of 5% aqueous sodium hydroxide solution were added to the mixture, the mixture was separated. The aqueous layer was separated and extracted twice with 10 ml of ethyl acetate. Then, each ethyl acetate layer was combined, washed successively twice with water and twice with a saturated saline solution, and dried over magnesium sulfate. After the resulting solution was concentrated, the residue was added small amount of benzene and left to stand. The precipitated crystals were collected by filtration, washed with benzene and dried over magnesium sulfate to obtain 280 mg of 7-[2-cyanomethylene-2-(2 formylaminothiazol-4-yl)acetamido]-3-(1-methyl-lH-tetra- zol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer B} (decomposition point: 148 # 1500C) as pale yellow crystals. 7-t-2-Cyanomethylene-2-(2-formylaminothiazol-4-yl)acet- amido] - 3- (1-methyl- IN-tetrazol- 5-yl) thiomethyl- 3-cephem- 4-carboxylic acid (Isomer B): IR (KBr): 2210, 1775, 1685, 1670 cm 1. NMR #ppm(d6-DMSO): 3.73 (bs, 2H), 3.93 (s, 3H), 4.32 (bs, 2H), 5.19 (d, J=SHz, 1H), 5.81 (dd, J=8Hz, 5Hz, 1H), 6.32 (s, 1H), 7.46 (s, 1H), 8.52 Cs, 1H), 9.90 (d, J=8Hz, 1H), 12.5 (bs, 1H). Example 14 A methanol solution (1.13 m & containing 85.7 mg of phosphorus oxychloride was ice-cooled. Subsequently, after 150 mg of 7-[2-cyanomethylene-2-(2-formylamino thiazol-4-yl) acetamido] -3- (l-methyl-lN-tetrazol-5-yl) - thiomethyl-3-cephem-4-carboxylic acid (Isomer B) was added to the methanol solution, the mixture was stirred for 45 minutes. After 5.6 ml of water was added to the mixture, the resulting mixture was stirred under icecooling. The precipitated crystals were collected by filtration, washed with water and dried to obtain 70 mg of 7-[2-cyanomethylene-2-(2-aminothiazol-4-yl)acetamido]3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid hydrochloride salt (decomposition point: 155 X 1600C) as pale yellow crystals. 7-[2-Cyanomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid hydrochloride salt (Isomer B): IR (KBr): 2220, 1770, 1710, 1665, 1615 cm NMR #ppm(d6-DMSO): 3.95 (s, 3H), 4.34 (qAB, J=13Hz, 2H), 5.22 (d, J=SHz, 1H), 5.83 (dd, J=8Hz, 5Hz, 1H), 6.16 (s, 1H), 6.89 (s, 1H), 9.91 (d, J=8Hz, 1H). Example 15 To a mixed solution composed of 2.6 mL of trifluoroacetic acid, 1.3 ml of anisole and 4.5 mQ of anhydrous methylene chloride, there was added 610 mg of 7-[2-cyanomethylene 2-(2-formylaminothiazol-4-yl)acetamidoJ-3-(1-methyl-lH- tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) under ice-cooling, and the mixture was stirred for 50 minutes. After 50 mt of ethyl acetate and 20 mQ of a 5% aqueous sodium hydroxide solution was added to the mixture, the mixture was separated. The aqueous layer was separated and extracted-twice with 10 mQ of ethyl acetate. Each ethyl acetate layer was combined, washed twice with water and then washed twice with a saturated saline solution, and dried over magnesium sulfate. After the solution was concentrated, the residue was added small amount of benzene and left to stand. The precipitated crystals were collected by filtration, washed with benzene and dried to obtain 450 mg of 7- [2-cyanomethylene-2- (2-formylaminothiazol-4-yl) - acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (Isomer A) (decomposition point: 128 # 1320C) as yellow crystals. 7-[2-Cyanomethylene-2-(2-formylaminothiazol-4-yl)acet amido] -3- Cl-methyl-lH-tetrazol-S-yl) thiomethyl'-3-cephem- 4-carboxylic acid (Isomer A): IR (KBr): 2210, 1775, 1710, 1670 cm NMR dppm(d6-DMSO): 3.73 (bs, 2H), 3.94 (s, 3H), 4.33 (bs, 2H), 5.16 (d, J=SHz 1H), 5.75 (dd, J=8Hz, 5Hz, 1H), 6.10 (s, 1H), 7.68 (s, 1H), 8.51 (s, 1H), 9.63 (d, J=8Hz, lH), 12.5 (bs, 1H). Example 16 A methanol solution (1.13 ml) containing 85.7 mg of phosphorus oxychloride was ice-cooled. Subsequently, after 150 mg of 7-[2-cyanomethylene-2-(2-formylamino hiazol-4-yl)acetamido]-3-(1-methyl-1B-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylic acid Isomer A) was added to the methanol solution, the mixture was stirred for 45 minutes. After 5.6 ml of water and 5 mQ of ethyl acetate were added to the mixture, the resulting mixture was adjusted to pH 2.5 with an aqueous sodium hydrogen carbonate solution and separated. The aqueous layer was separated, and washed twice with ethyl acetate. The ethyl acetate layer was combined, washed successive once with water and twice with ethyl acetate, and dried over magnesium sulfate. After the solution was concentrated, the residue was added small amount of benzene and left to stand. The precipitated crystals were collected by filtration, washed with benzene and dried to obtain 105 mg of 7-[2-cyanomethylene-2-(2-aminothiazol-4-yl)acet amido] -3- Cl-methyl-lH-tetrazol-S-yl) thiomethyl-3-cephem- 4-carboxylic acid (Isomer A) (decomposition point: 115# 1200C) as yellow crystals. 7-[2-Cyanomethylene-2-(2-aminothiazol-4-yl)acetamido]3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid (Isomer A): IR (KBr): 2220, 1775, 1715, 1670, 1610 cm 1. NMR dppm(d6-DMSO): 3.94 (s, 3H), 4.33 (qAB, J=13Hz, 2H), 5.17 (d, J=5Hz, 1H), 5.76 (dd, J=8Hz, 5Hz, 1H), 5.98 (s, 1H), 7.12 (s, 1H), 9.78 (d, J=8Nz, lN). Example 17 (1) After 700 mg of 7-12-cyanomethylene-2-(2-formylaminiothiazol-4yl)acetamido]-3-(1-methyl-1H-tetrazol-5 yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester was suspended in 3.4 ml of methanol and 7 mt of THF, 2 m± of 35% hydrochloric acid was added to the suspension. Subsequently, the mixture was stirred at room temperature over night. After 5 ml of water was added to the mixture under ice-cooling, the mixture was made to be weak alkaline by adding a saturated aqueous sodium hydrogen carbonate solution, and the resulting mixture was extracted three times with ethyl acetate. The extract was combined, washed successively twice with water and twice with a saturated saline solution, and dried over magnesium sulfate. Then, the solvent in the mixture was removed by evaporation under reduced pressure. The residue was purified by silica gel column chromatography to obtain 370 mg of 7-[2-(o-methylcarboxyimidoylmethy- lene)-2-(2-aminothiazol-4-yl)acetamido]-3-(1-methyl tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester Isomer A) as yellow crystals and 170 mg of 7-t2-carbamoylmethylene-2-(2-aminothiazol-4-yl)acet- amido] -3- C l-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem- 4-carboxylic acid benzhydryl ester (Isomer A) as pale brown amorphous crystals, respectively. 7-[2-(o-methylcarboxyimidoylmethylene)-2-(2-aminothiazol 4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid benzhydryl ester (Isomer A): IR CKBr): 1780, 1715, 1670, 1620 cm 1. NMR 6ppmCd6-DMSO): 3.68 (s, 3H), 3.78 (bs, 2H), 3.88 (s, 3H), 4.22 (d, J=14Hz, 1H), 4.41 (d, J=14Hz, 1H), 5.23 (d, J=5Hz, 1H), 5.87 (dd, J=8Hz, 5Hz, 1H), 6.38 (s, 1H), 6.83 (s, 1H), 6.92 Cs, 1H), 7.08 (bs, 3H), 7.37 (m, 10H), 9.59 (d, J=8Hz, 1H). 7-t2-carbamoylmethylene-2-(2-aminothiazol-4-yl)acetamid 3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester (Isomer A): IR (KBr): 1780, 1720, 1660, 1610 cm-1. NMR #ppm (d6-DMSO): 3.74 (bs, 2H), 3.86 (s, 3N), 4.19 Cd, J=14Hz, 1H), 4.39 (d, J=14Hz, 1H), 5.17 (d, J=5Hz, 1H), 5.88 (dd, J=8Hz, 5Hz, 1H), 6.59 (s, 1H), 6.77 Cs, 1N), 6.88 Cs, lN), 7.34 (m, 12H), 8.06 (bs, 2H), 9.52 (d, J=8Hz, 1H). (2) A mixed solution composed of 0.43 ml of trifluoroacetic acid, 0.21 ml of anisole and 0.72 ml of methylene chloride was ice-cooled. Subsequently, after 100 mg of 7-[2-(o-methylcarboxyLmidoylmethylene)-2-(2-aminothiazol- 4-al)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl 3-cephea-4-carboxylic acid benzhydryl ester was added to the mixed solution, the mixture was stirred for 1 hour. Then, 3 mt of ethyl acetate and 1 mt of water were added thereto, and the mixture was adjusted to pH 6.0 # 6.5 with a 10% aqueous sodium hydroxide solution under icecooling. The aqueous layer was separated, adjusted to pH 2.5 with 1N hydrochloric acid, and extracted with ethyl acetate. The extract was washed successively with water and twice with a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent yielded 60 mg of 7-[2-(o-methylcarboxyimidoylmethylene)- 2-(2-aminothiazol-4-yl)acetamido]-3-(1-methyl-1H-tetra zol-5-yl) thiomethyl-3-cephem-4-carboxylic acid (decom position point: 81 # 85 C) as pale yellow amorphous crystals. 7-[2- (o-Methylcarboxyimidoylmethylene) -2- (2-amino thiazol-4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylic acid: IR (KBr): 1780, 1715, 1665, 1630 cm 1 NMR dppm(d6-DMSO): 3.67 (bs, 5H), 3.93 (s, 3H), 4.30 (bs, 2H), 5.12 (d, J=SNz, 1H), 5.70 Cdd, J=8Hz, SHz, 1H), 6.43 (s, 1H), 6 24 (s, 1H), 9.54 (d, J=8Hz, 1H). Example 18 A mixed solution composed of 0.69 mt of trifluoroacetic acid, 0.34 mQ of anisole and 1.15 mL of methylene chloride was ice-cooled. Subsequently, after 160 mg of 7-[2-carbamoylmethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester was added to the mixed solution, the resulting mixture was stirred for 1 hour. Then, 1 mt of water was added thereto, and the resulting mixture was adjusted to pH 6.0 with a 10% aqueous sodium hydroxide solution. After the aqueous layer was washed with ethyl acetate, activated charcoal was addedthereto. The mixture was stirred and filtrated through membrane filter. After the filtrate was adjusted to pH 2.3 with 1N hydrochloric acid, the residue was stirred for 1 hour under ice-cooling. The precipitated crystals were collected by filtration, washed with water and dried to obtain 64 mg of 7-[2-carbamoylmethylene-2-(2-amino thiazol-4-yl)acetamido]-3-(1-methyl-lH-tetrazol-5-yl)- thiomethyl-3-cephem-4-carboxylic acid (decomposition point: 106 # 1100C). 7-[2-Carbamoylmethylene-2-t2-aminothiazol-4-yl)acet- amido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem4-carboxylic acid: IR (KBr): 1775, 1705, 1670, 1615 cm 1. NMR 6ppmCd6-DMSO): 3.62 Cd, J=18Hz, 1H), 3.80 (d, J=l8Hz, 1H), 3.91 (s, 3H), 4.22 (d, J=14Hz, 1H), 4.38 (d, J=14Hz, 1H), 5.14 (d, J=SHz, 1H), 5.72 (dd, J=8Hz, 1H), 6.46 (s, 1H), 6.98 (s, 1H), 6.2 X 7.6 (bs, 1H), 7.98 (bs, 1H), 8.52 (bs, 1H), 8.2 s 9.3 (bs, 2H), 9.62 (d, J= 8Hz, 1H). Example 19 (1) After 588 mg of 2-chloromethylene-2-(2-formylamino- thiazol-4-yl)acetic acid (Isomer A) and 1.41 g of 7amino-3-(1-benzhydryloxycarbonylmethyl-1H-tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester were dissolved in 35 ml of anhydrous THE, 494 mg of dicyclohexylcarbodiimide was added to the solution and the mixture was stirred at room temperature for 2 hours. The precipitates were collected by filtration, charged with a small quantity of water and THE was evaporated from the mixture. The residue was diluted with ethyl acetate and the insolubles were removed by filtration. Then, the filtrate was washed with an aqueous sodium hydrogen carbonate solution and then with water, and dried over magnesium sulfate. After concentration of the solution, the'concentrate was poured into 200 ml of ether. The precipitates were collected by filtration, washed with ether and dried to yield 1.31 g of 7-[2 chlóromethylene-2-(2-formylaminotiazol-4-yl)acetamido]-3- (1-benzhydryloxycarbonylmethyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) as pale brown crystals. 7-t2-Chloromethylene-2-(2-formylaminothiazol-4-yl)- acetamido]-3-(1-benzhydryloxycarbonylmethyl-lH-tetrazol- 5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A): NMR dmmp(d6-DMSO): -3.69 (bs, 2H), 4.30 (bs, 2H), 5.20 (d, J=SHz, lN), 5.62 Cs, 2H), 8.51 (s, 1H). (2) 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl) acetamido]-3-(1-benzhydryloxyearbonylmethyl-lH-tetrazol- 5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (500 mg) (Isomer A) was dissolved in 5 mt of methanol and 2 mt of THF. Under ice-cooling and stirring, 0.2 ml of phosphorus oxychloride was added to the solution and the mixture was stirred at room temperature for one hour. Then, with addition of water and ethyl acetate, the mixture was extracted with ethyl acetate, and the extract was washed with a saturated aqueous sodium hydrogen carbonate solution and then with water, followed by drying over magnesium sulfate. Evaporation of the solvent under reduced pressure gave 520 mg of amorphous crystals, which was then purified by column chromatography to yield 215 mg of 7-[2-chloromethylene 2-(2-aminothiazol-4-yl)acetamido]-3-(1-benzhydrylOxy- carbonylmethyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester (Isomer A) as yellow crystals. 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido] 3-(1-benzhydryloxycarbonylmethyl-lH-tetrazol-5-yl)thio- methyl3-cephem-4-carboxylic acid benzhydryl ester (Isomer A): NMR #ppm (d6-DMSO): 5.16 (d, J=SHz, 1H), 5.62 (s, 2H), 5.88 (dd, J= 7Hz, 5Hz, 1H), 6.40 (s, 1H), 6.85 (s, 3H), 9.61 (d, J=7Hz, 1H). (3) 7-[2-Chlormethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-benzhydryloxycarbonylmethyl-1H-tetrazol-5yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) (210 mg) was dissolved in 0.2 mQ of anhydrous methylene chloride, and then 0.2 mQ of anisole was added to the solution. Under ice-cooling, 0.4 mt of trifluoroacetic acid was added to the resulting mixture and the mixture was stirred for one hour. The reaction mixture was poured into an aqueous sodium hydrogen carbonate solution and adjusted to pH 7.5. After washing with ethyl acetate, pH of the mixture was adjusted to 2.9 with a 10% phosphoric acid. The precipitated crystals were collected by filtration, washed with water and dried to yield 40 mg of 7-[2-chloromethylene-2-(2-aminothiazol-4 yl)acetamido]-3-(1-carboxymethyl-lH-tetrazol-5-yl)thio- methyl-3-cephem-4-carboxylic acid (Isomer A) as pale brown crystals (decomposition point: 196 2000C). 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-carboxymethyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid (Isomer A): NMR dppm(d6-DMSO): 3.58 (d, J=19Hz, 1H), 3.77 (d, J=19Hz, 1H), 4.22 Cd, J=l4Hz, 1H), 4.46 Cd, J=14Hz, 1H), 5.14 (d, J=SHz, 1H), 5.25 (s, 2H), 5.80(dd, J=7Hz, 5Hz, 1H), 6.38 (s, 1H), 6.83 (s, 1H), 7.17 (bs, 2N), 9.60 (d, J=7Hz, 1H) Example 20 (1) After 0.9 g of 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A) and 2.0 g of 7-amino3-(2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester were dissolved in 90 mt of THF, 0.91 g of dicyclohexylcarbodiimide was added to the solution and the mixture was stirred at room temperature for 2 hours. After the pricipitates were removed by filtration, the solution was concentrated and the residue was poured into ether. The precipitates were collected by filtration and dried to yield 1.45 g of 7-[2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) as brown amorphous crystals. 7-12-Chloromethylen-2-(2-formyl2minothiazol-4-yl)- acetamido]-3-(2-methylthio-1,3,4-thiadiazol-5-yl)- thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A): NMR dppm(d6-DMSO): 2.70 (s, 3H), 3.75 (bs, 2H), 4.28 (m, 2H) 5.25 (d, J=SHz, 1H), 5.92 (dd, J=8Hz, 5Hz, 1H), 6.90 (bs, 1H), 7.08 (bs, 1H), 7.35 (m, 10H), 8.52 (s, 1H), 9.62 (d, J=8Zz, 1H) (2) 7-{2-Chloromethylene-2-(2-formylaminothiazol-4-yl)- acetamido]-3-(2-methylthio-1,3,4-thiadiazol-5-yl)thio- methyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) (1.4 g) was dissolved in 17 mt of methanol and 10 mt of THF. Under ice-cooling and stirring, 1.13 g of phosphorus oxychloride was added to the solution and the mixture was stirred at room temperature for one hour. Then, with addition of ethyl acetate, the mixture was washed with water, with an aqueous sodium hydrogen carbonate solution and then with water. The solution was concentrated, the residue was poured into ether, and the precipitates were collected by filtration, followed by drying to yield 0.7 g of 7-[2-chloromethylene-2-(2- aminothiazol-4-yl) acetamido] -3- C2-methylthio-l, 3,4- thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) as brown amorphous crystals. 7-[2-Chloromethylene-2-t2-aminothiazol-4-yl)acetamido]- 3-(2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylic acid benzhydryl ester (Isomer A): NMR dppm(d6-DMSO): 2.69 (s, 3H), 3.78 (bs, 2H), 4.18 (m, 2H) 5.30 Cd, J=5Hz, 1H), 5.90 (dud, J=8Nz, 5Ez, 1g), 6.92 (bs, 1H), 7.36 (m, 10H), 9.62 (d, J=8Hz, 1H) (3) 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) (0.7 g) was dissolved in 5 mQ of methylene chloride, and then 0.31 g of anisole was added to the solution. Under ice-cooling, 0.92 g of trifluoroacetic acid was added dropwise to the resultant mixture and the mixture was stirred at the same temperature for 1.5 hour. After evaporation of the solvent, the residue was adjusted to pH 7.0 with an aqueous sodium hydrogen carbonate solution. After washing with ethyl acetate, the mixture was adjusted to pH 3.2 with 1N hydrochloric acid. The resultant precipitates were collected by filtration, washed with water and dried to yield 80 mg of 7-[2-chloromethylene- 2-(2-aminothiazol-4-yl)acetamido]-3-(2-methylthio-1,3,4- thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as yellow amorphous crystals (decomposition point: 165 N 1680C). 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]3-(2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3cephem-4-carboxylic acid (Iromer A): NMR dppm(d6-DMSO): 2.73 Cs, 3H), 3.59 Cd, J-17Hz, 1H), 3.75 (d, J=17Hz, 1H), 4.21 Cd, J=l2Hz, 1H), 4.48 (d, j=l2Hz, lH), 5.18 Cd, J=5Hz, 1H), 5.78 (dd, J=7Hz, 5Hz, 1H), 6.39 (s, 1H), 6.83 Cs, lH), 7.16 (bs, 2H), 9.59 (d, J=7Hz, 1H) Synthesis example 9 Cl) A suspension of 654 mg of bromomethyl triphenylphosphonium bromide in 5 m# of anhydrous THF was cooled under nitrogen stream to -180C, and 72 mg of sodium hydride was added thereto, followed by stirring under ice-cooling for 3 hours. Subsequently, 228 mg of ethyl (2-formylaminothiazol-4-yl)qlyaxylate was added to the resulting mixture, followed further by stirring under ice-cooling for 1.5 hour and at room temperature for 1.5 hour. Then, 10 mt of ethyl acetate and 3 m# of water were added to the reaction mixture and the pH of the mixture was adjusted to 6 with 1N hydrochloric acid. The ethyl acetate layer was separated, and the aqueous layer was extracted again with 10-mi of ethyl acetate. The extracts were combined and washed with water ( x 2) and then with a saturated aqueous sodium chloride solution ( x 2), followed by drying over magnesium sulfate. The solution was concentrated under reduced pressure and the residue was purified by column chromatography to yield 150 mg of ethyl 2-bromomethylene-2-(2-formylaminothiazol4-yl) acetate. Ethyl 2-bromomethylene-2-(2-formulaminothiazol-4-yl)acetate: IR (KBr): 1730, 1660, 1560 cm 1 NMR dppm(d6-DMSO): 1.23 (t, J=7Ez, 3H), 1.31 (t, 7Hz, 3N), 4.17 (q, J=7Hz, 2H), 4.33 (q, J=7Hz, 2H), 7.25(s, 1H), 7.33 (s, 1H), 7.38 (s, 1H), 7.85 (s, 1H), 8.46(s, 1H), 8.48 (s, 1H), 12.3 (bs, 1H), 12.4 (bs, 1H (2) Ethyl 2-bromomethylene-2-(2-formylaminothiazol-4yl)acetate (912 mg) was added, under ice-cooling, to 22.4 m# of 3% aqueous potassium hydroxide solution, followed by stirring at the same temperature for 7.5 hours. Then, under ice-cooling, the reaction mixture was adjusted to pH 2.7 with a 10% phosphoric acid and stirred for 30 minutes. The precipitated crystals were collected by filtration, washed with water and dried to yield 720 mg of 2-bromomethylene-2-(2-formylaminothiazol-4-yl)acetic acid as pale-yellow crystals. 2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetic acid: IR. (KBr): 3570, 1680, 1565 cm-1. NMR dppm(d6-DMSO): 7.23 (s, 2H), 8.48 (s, 1H), 12.4 (bs, 1H). Example 21 (1) After 670 mg of 2-bromomethylene-2-(2-formylamino- thiazol-4-yl)acetic acid and 1.09 g of 7-amino-3-(1 methyl-1E-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester were suspended in 15 m± of anhydrous THF, 589 mg of dicyclohexylcarbodiimide was added to the suspension and the mixture was stirred at room temperature for 3 hours. After insolubles were removed by filtration, the filtrate was concentrated under reduced pressure and the residue was purified by column chromatography to yield 1.26 g of 7-[2-bromomethylene-2 (2-formylaminothiazol-4-yi) acetamido3 -3- (l-methyl-lN- tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester as pale yellow amorphous crystals. 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamidol-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl -3-cephem4-carboxylic acid benzhydryl ester: IR (KBr): 1785, 1720, 1685, 1670, 1540 cm 1. NMR dppm(d6-DMSO): 3.76 (bs, 2H), 3.87 (s, 3H), 4.28(bs, 2H) 5.26 (d, J=SHz, 1H), 5.93 (dd, J=8Hz, 5Hz, lH), 6.89 (s, lH), 7.10 (s, 1H), 7.20 Cs, 1H), 7.35 (m, 10H, 8.49 (s, 1H), 9.65 (d, J=8Hz, 1H). (2) To a suspension of 870 mg of 7-[2-bromomethylene-2- (2-formylaminothiazol-4-y')acetamido]-3-(1-methyl-1E- tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester in 11 ml of absolute methanol, there was added dropwise under ice-cooling 0.53 ml of phosphorus oxychloride, followed by stirring at room temperature for one hour. Then, 50 ml- of ethyl acetate and 10 ml of water were added to the resulting mixture, and the mixture was adjusted to pH 7.5 with a saturated aqueous sodium hydrogen carbonate solution. The ethyl acetate layer was separated1 and the aqueous layer extracted again with 30 m# of ethyl acetate. The extracts were combined, washed with water, then with a saturated aqueous sodium chloride solution and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure yielded 740 mg of 7-[2-bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester as pale yellow amorphous crystals. 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4 carboxylic acid benzhydryl ester: IR (KBr): 1780, 1720, 1670, 1610, 1525 cm 1. NMR 6ppm(d6-DMSO): 3.78 (bs, 2H), 3.88 Cs, 3H), 4.28(bs, 2H) 5.24 (d, J=SHz, lH), 5.88 (dud, J-SHz, 5Hz, 1E), 6.46 (s, 1H), 6.90 (s, 1H), 6.98 (s, 1H), 7.10 (bs, 2H), 7.35 (m, 10H), 9.60 Cd, J=8Hz, 1H). (3) 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acet- amido] - 3- C 1-methyl- lH-tetrazol- 5-yl) thiomethyl- 3-cephem- 4¯carboxylic acid benzhydryl ester (290 mg) was dissoved in 2.07 mt of anhydrous methylene chloride and 0.61 mi of anisole. Under ice-cooling, 1.25 mi of trifluoroacetic acid was added to the resulting mixture, and the mixture was stirred at the same temperature for one hour. Then, 7 mi of ethyl acetate and 2 mi of water were added to the resulting mixture and pH of the mixture was adjusted to 6.5 under ice-cooling with a 10% aqueous sodium hydroxide solution. The aqueous layer was separated and the ethyl acetate layer was extracted again with 1 mi of water. The extracts were combined and stirred with 50 mg of activated charcoal, followed by filtration through a membrane filter. The filtrate was adjusted under ice-cooling to pH 2.5 with 1N HCQ and the residue was stirred at the same temperature for one hour. The precipitated crystals were collected by filtration, washed with water and dried to yield 150 mg of 7-[2 bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1- methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as pale orange amorphous crystals (decomposition point: 157 X 1630C). 7-12-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid: IR (KBr): 1770, 1660, 1625, 1525 cm 1. NMR dppm(d6-DMSO): 3.68 (bs, 2H), 3.92 (s, 3H), 4.29 (bs, 2H), 5.15 (d, J=SHz, 1H), 5.77 (dd, J=8Hz, 5Hz, 1B), 6.40 Cs, lH), 6.95 (s, 1H), 9.50 (d, J=8Hz, 1B}. Synthesis example 10 (1) Sodium ethoxide (136.1 g) was added to 759 mQ of ethanol, and the mixture was cooled under stirring to room temperature, and then 148.2 g of ethyl formate was added thereto. Subsequently, 93.1 g of ethyl (2-aminothiazol-4-yl)acetate was added to the resulting mixture and the mixture was stirred for 3 hours. Then, 100 mQ of water was added to dissolve the product and the solution was adjusted to pH 5.2 with 1N HCQ. The precipitated crystals were collected by filtration and dried to yield 95.1 g of ethyl 2-formyl-2-(2-formylaminothiazol-4- yl)acetate as pale brown crystals. (2) Ethyl 2-formyl-2-(2-formylaminothiazol-4-yl)acetate (121 g) was suspended in 365 g of anhydrous DMF, and under ice-cooling 50 mQ of phosphorus oxychloride was added dropwise thereto. Then, the mixture was returned to room temperature, followed by stirring at 95 to 1000C for 3 hours. After cooling, the reaction mixture was charged with a mixture of 250 mQ of water and 500 mi of ethyl acetate and adjusted to pH 7.0 with a 10% aqueous sodium hydroxide solution. The ethyl acetate layer was separated and the aqueous layer was extracted twice with 500 mi of ethyl acetate. The ethyl acetate layers were combined, washed with water ( x 3) and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure yielded 138.3 g of ethyl 2-chloromethylene-2 (2-dimethylaminomethyleneaminothiazol-4-yl)acetate as dark brown oil. Ethyl 2-chloromethylene-2-(2-dimethylaminomethyleneaminothiazol-4-yl)acetate: NMR dppm(d6-DMSO): 1.23 (t, J=7Hz, 3H), 1.30 (t, J=7Hz, 3H), 2.97 (s, 6H), 3.14 Cs, 6H), 4.19 (q, J=7Hz, 2H), 4.32 (q, J=7Hz, 2E), 6.93 (s, 1H), 7.14 (s, 1H), 7.23 (s, 1H), 7.52 (s, 1H), 8.23 (s, lH), 8.30 (s, 1H) (3) Into 102 g of acetic anhydride, under ice-cooling and stirring, there was added dropwise 50.6 g of formic acid and the mixture was stirred at S0CC for 30 minutes. After cooling, this mixed acid anhydride was added, under ice-cooling and stirring, to 183.3 g of ethyl 2-chloromethylene-2-(2-dimethylaminomethyleneaminothiazol-4-yl)acetate. After one hour, the mixture was returned to room temperature, followed by stirring for 18 hours. The reaction mixture was charged with a mixed solution of 250 mt of water and 500 mQ of ethyl acetate and adjusted to pH 6.0 with a 10% aqueous sodium hydroxide solution. The ethyl acetate layer was separated and the aqueous layer was again extracted with 500 mL of ethyl acetate. The ethyl acetate layers were combined, washed with a saturated aqueous sodium hydrogen carbonate solution, then with water and dried over magnesium sulfate. After evaporation of the solvent under reduced pressure, the residue was diluted with 100 mQ of chloroform and left to stand for 2 days. The precipitated crystals were collected by filtration, washed with a small quantity of chloroform and then with benzene, followed by drying, to yield 36.6 g of ethyl 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetate (Isomer A) as yellowish white crystals. The mother liquor was subjected to silica gel chromatography to be purified to obtain 5.23 g of the same substance. (4) Ethyl 2-chloromethylene-2-(2-formylaminothiazol-4- yl)acetate (Isomer A) (10 g) was suspended in 50 mi of water, and to the resultant suspension, under ice-cooling and stirring, there was added dropwise 50 my of water containing 6.46 g of sodium hydroxide over 10 minutes, followed by stirring at the same temperature for 3 hours. Then, the mixture was adjusted to pH 2.5 with 1N HCt and the precipitated crystals were collected by filtration, washed with water and dried to yield 8.82 g of 2-chloro methylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A) as colorless crystals. (5) Into 35 ml of acetonitrile, there were added 4.0 g of 2-ethylthio-5-mercaptothiadiazole and 6.11 g of 7aminocephalosporanic acid. Then, 8.51 mi of boron trifluoride ethylether complex was added dropwise under stirring to the mixture, followed by stirring at 450C for one hour. After cooling, the reaction mixture was poured into 100 mQ of water and adjusted to pH 4.0 with an aqueous ammonia solution. After evaporation of acetonitrile, the solution was further concentrated and the residue was left to stand for 3 days. The precipitated crystals were collected by filtration, washed with water and dried to yield 7.04 g of 7-amino-3-(2-ethylthio 1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as brown crystals. Example 22 (1) To a solution prepared by dissolving 2.0 g of 7 amino-3- (2-ethylthio-l, 3, 4-thiadiazol-5-yl) thiomethyl-3- cephem-4-carboxylic acid and 2.08 g of N,N-bis(trimethylsilyl)acetamide in 30 mi of methylene chloride, there was added a solution prepared by dissolving 2.38 g of 2 chloromethylene-2-(2-fOrmylaminothiazol-4-yl)acetic acid (Isomer A) in 30 mQ of THF and stirring the resulting solution with 1.06 g of dicyclohexylcarbodiimide at room temperature for 2 hours. The mixture was then stirred at room temperature for 60 hours. The solution was concentrated to dryness, and the'residue was diluted with water and adjusted to PH 7.5 with an aqueous sodium hydrogen carbonate solution to be dissolved therein. After insolubles were removed by filtration, the solution was washed with ethyl acetate and adjusted to pH 4.0 with 1N HCL. The precipitated product was removed by filtration, and the filtrate was adjusted to pH 3.0. The precipitate was collected by filtration, washed with water and dried to yield 0.62 g of 7-[2-chloromethylene-2-(2 formylaminothiazol-4-yl)acetamido]-3-(2-ethylthio-1,3,4- thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as yellow amorphous crystals. 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-ethylthio-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid (Isomer A): NMR dppm(d6-DMSO): 1.37 Ct, J=7Ez, 3H), 3.28 (q, J=7Hz, 2H), 3.72 (bs, 2H), 4.20 (d, J=l4Hz, 1H), 4.58 Cd, J=l4Hz, 1H), 5.22 (d, J=5Hz, lH), 5.85 (m, IH), 7.08 (bs, 2H), 8.52(s, 1H, 9.64 (d, J=8Hz, 1E), 12.40 (bs, 1H) (2) 7- [2-Chloromethylene-2- (2-formylaminothiazol-4-yl) acetamido]-3-(2-ethylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) (0.62 g) was dissolved in a mixed solvent composed of 6 mQ of THF and 6 m# of methanol, and to the resulting solution, under ice-cooling and stirring, there was added 0.18 mQ of ccnc. HCQ, followed by stirring at room temperature for 18 hours. After evaporation of the solvent, 20 mt of water was added to the residue. The precipitates were collected by filtration, washed with water and dried to yield 0.45 g of 7-[chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(2-ethylthio-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid hydrochloride (Isomer A) as brown amorphous. crystals (decomposition point: 2200C). 7-12-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]- 3-(2-ethylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem- 4-carboxylic acid hydrochloride (Isomer A): NMR 6ppm(d6-DMSO): 1.35 (t, J=7Hz, 3E), 3.26 (q, J=7Nz, 2H), 3.71 (bs, 2H), .36 (m, 2H), 5.20 (d, J=SHz, 1H), 5.78 (m, 1H), 6.42 (s, 1H), 6.88(s, 1H), 9.55 (d, J=7Hz, 1H) Example 23 (1) 7- [2-Chloromethylene-2- (2-formylaminothiazol-4-yl) - acetamidolcephalosporanic acid (Isomer A) (244 mg) was dissolved in 3 mt of anhydrous DMF and 60 mg of potassium hydrogen carbonate was added to the solution. Then, under ice-cooling, 111 mg of l-bromo-3-oxoisobenzofuran was added to the resulting mixture and the mixture was stirred at room temperature for 3 hours. The reaction mixture was charged with ethyl acetate, washed with water, an aqueous sodium hydrogen carbonate solution and then water, followed by drying over magnesium sulfate. Evaporation of the solvent yielded 220 mg of 7-[2-chloro- methylene-2-(2-formylaminothiazol-4-yl)acetamido]cephalosporanic acid l-oxoisobenzofuran-3-yl ester (Isomer A) as yellow crystals. (2) 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl) acetamido]cephalosporanic acid l-oxoisobenzofuran-3-yl ester (Isomer A) (420 mg) was dissolved in an ice-cooled mixture of 5 mt of absolute methanol, 92 mg of phosphorus oxychloride and S mQ of anhydrous THF, and the mixture was stirred under ice-cooling for 4 hours. The reaction mixture was adjusted to pH 6 with a saturated aqueous sodium hydrogen carbonate solution, followed by evaporation of methanol and THF. The concentrate was adjusted to pH 7 and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate and then purified by silica gel chromatography to yield 65 mg of 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]cephalosporanic acid l-oxoisobenzofuran-3-yl ester (Isomer A) as colorless crystals (decomposition point: 120 X 1240C). 7-12-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido]- cephalosporanic acid l-oxoisobenzofuran-3-yl ester (Isomer A): NMR dppm(d6-DMSO): 4,66 (bs, 2H), 6.46 (s, 1H), 7.53 (s, 1H), 9.60 (d, J=8Hz, 1R). Example 24 (1) To 973 mg of 7-[ 2-Chloromethylene-2- (2-formylamino- thiazol-4-yl) acetamido] cephalosporanic acid (Isomer A), there were added 12 mQ of anhydrous DMF, 240 mg of potassium hydrogen carbonate and 100 mg of crown ether (18-6). Under ice-cooling, 361 mg of chloromethyl pivalate was added to the mixture, followed by stirring for one hour. Then, the mixture was subjected to stirring at room temperature overnight. The reaction mixture was charged with water and extracted with ethyl acetate. The extract was washed with an aqueous sodium hydrogen carbonate solution, then with water and dried over magnesium sulfate. After evaporation of the solvent under reduced pressure, the residue was subjected to silica gel chromatography for purification to yield 180 mg of the crystals of 7-[chloromethylene-2-(2-formylaminothiazol 4-yl) acetamido] cephalosporanic acid pivaloyloxymethyl ester (Isomer A). 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido] cephalosporanic acid pivaloyloxymethyl ester (Isomer A): NMR #ppm (CDC#3): 1.25 (s, 9H), 2.10 (s, 3H), 3.56 (bs, 2H), 5.90 (s, 2H), 6.83 Cs, lH), 7.03 Cs, 1H), 8.50 (s, 1H). (2) 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]cephalosporanic acid pivaloyloxymethyl ester (Isomer A) (150 mg) was dissolved in 1 m# of anhydrous THF, and 1 mt of absolute methanol and 38 mg of phosphorus oxychloride were added to the resulting solution under ice-cooling, followed by stirring for 3 hours. The reaction mixture was adjusted to pH 7 with a saturated aqueous sodium hydrogen carbonate solution, concentrated and the residue was extracted with ethyl acetate. The extract was washed with a saturated aqueous sodium hydrogen carbonate solution, then with water and dried over magnesium sulfate. After evaporation of the solvent under reduced pressure, the residue was subjected to silica gel chromatography for purification to yield 86 mg of 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]cephalosporanic acid pivaloyloxymethyl ester (Isomer A) as pale yellow crystals (decomposition point: 91 X 1010C). 7-[2-Chloromethylene-2-(2-aminothiazol-4-yl)acetamido] cephalosporanic acid pivaloyloxymethyl ester (Isomer A): NMR dppm(d6-DMSO): 1.16 Cs, 9H), 2.05 (s, 3H), 6.40 Cs, 1H), 6.86 (s, 1H), 7.10 (bs, 2H), 9.55 (d, J=8Hz, 1H) Example 25 (1) After 2.5 g of 2-bromomethylene-2-(2-formylaminothiazol-4-yl)acetic acid and 4.07 g of 7-amino-3-(1,3,4thiadiazol-2-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester were suspended in 55 mL of anhydrous THF, 2.2 g of dicyclohexylcarbodiimide was added thereto, and the mixture was stirred at room temperature for 3 hours. After removal by filtration of insolubles, the mother liquor was concentrated and the residue was purified by silica gel chromatography to yield 4.95 g of 7 [2-bromÏmethylene-2-(2-formylaminothiazol-4-yl)acet- amido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester as pale orange amorphous crystals. 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl1-3-cephem-4carboxylic acid benzhydryl ester. IR (KBr): 1780, 1715, 1670 cm NMR #ppm(d6-DMSO): 3.78 (bs, 2H), 4.25 (d, J=13Hz, 1H), 4.55( d, J=13Hz, 1H), 5.30 Cd, J=5Hz, 1H), 5.95 (dd, J=SHz, 8Hz, 1H), 6.95 (s, 1H), 7.13 (s, 1H), 7.23 (s, 1H), 7.35 (m, 10H), 8.55 (s, 1H), 9.51 (s, 1H), 9.69 (d, J=8Hz, 1H). (2) 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl) acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester (450 mg) was suspended in 5 mL of absolute methanol, and 0.22 mQ of phosphorus oxychloride was added dropwise under ice-cooling to the suspension, followed by stirring at room temperature for one hour. The reaction mixture was charged with 30 mQ of ethyl acetate and 10 mQ of a saturated aqueous sodium hydrogen carbonate solution, followed by separation of the layers. The ethyl acetate layer was washed with water and then with a saturated aqueous sodium hydrogen carbonate solution, and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure yielded 378 mg of 7-[2-bromomethylene-2-(2-aminothiazol-4-yl)- acetamido3-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem- 4-carboxylic acid benzhydryl ester as pale yellow amorphous crystals. 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester: IR (KBr): 1770, 1715, 1660, 1610 cm 1. NMR 6ppm(d6-DMSO): 3.74 (bs, 2H), 4.23 (d, j=13Hz, 1H), 4.52( d, J=13Hz, 1H), 5.25 (d, J=SHz, 1H), 5.88 (dd, J=SHz, 8Hz, lH), 6.44 (s, 1H), 6.92 (s, 1H), 6.98 (s, 1H), 7.10 (bs, 2H), 7.37 (m, 10H), 9.46 (s, 1E), 9.57 (d, J=8Hz, 1H). (3) 7-[2-Bromomethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester (378 mg) was dissolved in 0.8 m# of anhydrous methylene chloride and 0.4 mi of anisole and, under ice-cooling, 0.8 mi of trifluoroacetic acid was added dropwise to the resulting solution, followed by stirring at the same temperature for 1.5 hours. The reaction mixture was charged with 5 m# of ethyl acetate and 1 m# of water, adjusted to pH 8.0 with a 10% aqueous sodium hydroxide solution under- icecooling, and the aqueous layer was separated. The ethyl acetate layer was extracted again with 1 mt of water. The aqueous layers were combined and adjusted to pH 7.0 with 1N HCt. The precipitates were collected by filtration, adjusted to pH 2.7 with 1N HCL and stirred under ice-cooling for 2 hours. The precipitated crystals were collected by filtration, washed with water and dried to yield 108 mg of 7-[2-bromomethylene-2-(2-aminothiazol-4- yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3cephem-4-carboxylic acid as pale yellow crystals (decomposition point: 138 # 1420C). 7-t2-Bromomethylene-2-(2-aminothiazol-4-yl)acetamido]- 3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid: IR CKBr): 1765, 1650 cm 1. NMR #ppm(d6-DMSO): 3.67 (bs, 2H), 4.29 (d, J=13Hz, 1H), 4.56( d, J=13Hz, lH), 5.15 (d, J=5Hz, 1H), 5.74 (dd, J=SHz, 8Hz, 1H), 6.40 (s, 1z), 6.94 (s, 1H), 7.11 (bs, 2H), 9.49 (d, J=8Hz, lH), 9.50 (s, 1H) (4) 7- [2-Bromomethylene-2- (2-formylaminothiazol-4-yl) acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester (4.7 g) was dissolved in 9.6 mQ of anhydrous methylene chloride and 4.8 m# of anisole and, under ice-cooling, 9.6 mQ of trifluoroacetic acid was added dropwise to the resulting solution, followed by stirring at the same temperature for 2.5 hours. Then, 47 mQ of anhydrous ethyl acetate, further 47 mQ of anhydrous n-hexane were added dropwise, and the mixture was stirred under ice-cooling for one hour. The precipitated crystals were collected by filtration, washed with ethyl acetate : n-hexane (1 : 1) and dried to yield 3.28 g of 7-[2-bromomethylene-2-(2-formylamino- thiazol-4-yl)acetamidol-3-(1,3,4-thiadiAzol-2-yl)thio- methyl-3-cephem-4-carboxylic acid as pale yellow crystals. 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4carboxylic acid: IR (KBr): 1775, 1665 cm NMR ppmCd6-DMSO): 3.73 (bs, 2H), 4.28 Cd, J=14Hz, 1B), 4.61( d, J=14Hz, 1H), 5.22 (d, J=5Hz, 1H), 5.83 (dd, J=5Hz, 8Hz, 1H), 7.09 (s, lH), 7.19 (s, 1H), 8.50(s, 1S), 9.52 (s, lH), 9.60 (d, J=8Hz, 1E), 12.3 (bs, 1H) (5) 7-[Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem4-carboxylic acid (295 mg) was dissolved in 1 m# of THF and 1 mQ of methanol, and 0.15 mQ of conc. HC# was added to the resulting solution under ice-cooling, followed by stirring at room temperature for 3 hours and 15 minutes. The reaction mixture was charged with 2 mQ of water and adjusted under ice-cooling to pH 7.5 with a saturated aqueous sodium hydrogen carbonate solution. After evaporation of the organic solvent under reduced pressure, the residue was adjusted to pH 5.5 with 1N HC# and the precipitates were removed by filtration. Then, the filtrate was adjusted to pH 3.0 and stirred under icecooling for one hour. The precipitated crystals were collected by filtration, washed with water and dried to yield 150 mg of 7-[2-bromomethylene-2-(2-aminothiazol-4- yl)acetamidoJ-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3- cephem-4-carboxylic acid as pale yellow crystals. Example 26 (1) After 609 mg of 2-bromomethylene-2-(2-formylamino- thiazol-4-yl)acetic acid and 1.02 g of 7-amino-3-(2 methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester were suspended in anhydrous THF, 536 mg of dicyclohexylcarbodiimide was added to the suspension and the mixture was stirred at room temperature for 4.5 hours. After the insolubles were removed by filtration, the solution was subjected to silica gel chromatography for purification to yield 1.46 g of 7-[2-bromomethylene-2-(2-formylaminothiazol-4-yl) acetamido]-3-(2-methy'-1,3,4-thiadiazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid benzhydryl ester as pale orange amorphous crystals. 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl) acetamidol-3-(2-methyl-1,3,4-thiadiazol-5-yl)-thiomethyl- 3-cephem-4-carboxylic acid benzhydryl ester: IR (KBr): 1780, 1715, 1670 cm 1 NMR 6ppmCd6-DMSO): 2.63 (s, 3H), 3.73 (bs, 2H), 4.16 (d, J=13Hz, 1H), 4.48(d, J=13Hz, 1H), 5.26 (d, J=5Hz, lH), 5.92 (dd, J=SHz, 8Hz, 1H), 6.91 (s, 1H), 7.09 (s, 1H), 7.19 (s, 1E), 7.34 (m, 10H), 8.49 (s, 1H), 9.63 (d, J=8Hz, 1H) (2) 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid benzhydryl ester (450 mg) was dissolved in 0.9 mQ of anhydrous methylene chloride and 0.45 mQ of anisole. Under ice-cooling, 0.9 m# of trifluoroacetic acid was added dropwise to the solution and the mixture was stirred at the same temperature for 3.5 hours. The reaction mixture was charged with 5 mQ of ethyl acetate, and the mixture was stirred under icecooling for one hour. The precipitated crystals were collected by filtration, washed with ethyl acetate and dried to yield 300 mg of 7-[2-bromomethylene-2-(2 formylaminothiazol-4-yl)acetamidol-3-(2-methyl-1,3,4- thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as pale yellow crystals. 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl) acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl- 3-cephem-4-carboxylic acid: IR (KBr): 1765, 1665 cm NMR #ppm(d6-DMSO): 2.68 (s, 3H), 3.69 (bs, 2H), 4.20 (d, J=13Hz, 1H), 4.53 (d, J=13Hz, 1R), 5.18 (d, J=5Hz, 1H), 5.80 (dd, J=SNz, 8 Hz, lH), 7.06 (s, 1H), 7.15 (s, 1H), 8.48 (s, lH), 9.56 (d, J=8Hz, 1H), 12.4 (bs, 1H) (3) 7-[2-Bromomethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl3-cephem-4-carboxylic acid (233 mg) was dissolved in 1 m# of absolute methanol and 1 m# of anhydrous THF. Under ice-cooling, 0.07 mi of phosphorus oxychloride was added dropwise to the resulting solution and the mixture was stirred at room temperature for one hour. One mQ of water was added to the reaction mixture under ice-cooling and, after adjustment of pH to 3.2 with a saturated aqueous sodium hydrogen carbonate solution, stirring was conducted for one hour. The precipitated crystals were collected by filtration, washed with water and then ethyl acetate, followed by drying, to yield 184 mg of 7-[2-bromomethy lene-2-(2-aminothiazol-4-yl)acetamido]-3-(2-methyl-1,3,4- thiadiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as pale brown crystals (decomposition point: 140 X 1430C). 7-12-Bromomethylene-2-(2-aminothiazol-4-yl)acetamidO]- 3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem-4carboxylic acid: NMR 6ppmCd6-DMSO): 2.67 (s, 3H), 3.67 (bs, 2H), 4.20 (d, J=13Hz, 1H), 4.52 (d, J=13Hz, 1H), 5.16 (d, J=SHz, 1H), 5.77 (dd, J=5Hz, 8Hz, 1H), 6.40 (s, 1H), 6.95 (s, 1H), 7.08 (bs, 2H), 9.48 (d, J=8Hz, 1H) Example 27 (1) 2-Chloromethylene-2-(2-formylaminothiazol-4-yl)acetic acid (2.0 g, 0.0086 mol) (Isomer A) and 7-amino 3- (l-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4- carboxylic acid benzhydryl ester (4.25 g, 0.0086 mol) were dissolved in a mixed solvent composed of tetrahydrofuran-methylene chloride (300 mt, 1 : 2). To the resulting solution was added dicyclohexylcarbodiimide (1.77 g, 0.0086 mol), and the mixture was stirred at room temperature for 4 hours. To the reaction mixture was added N,N'-dicyclohexylcarbodiimide (0.177 g, 0.00086' mol), and the mixture was stirred for additional one hour at room temperature. The mixture was concentrated under reduced pressure and the residue was diluted with methylene chloride (80 m#) and subjected to filtration. The filtrate was concentrated under reduced pressure to obtain an oily product. This product was purified by column chromatography to yield 7-[2-chloromethylene-2 (2-formylaminothiazol-4-yl)acetamido]-3-(1-methyl-lH- tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester as pale yellow powders (Isomer A) (4.92 g, 81%). NMR #ppm(CDC#3): 3.66 (m, 2N), 3.72 (s, 3H), 4.26 (m, 2H), 5.07 (d, J=6Hz, 1H), 5.92 (dd, J=4.5Hz, 6Hz, 1H), 6.76 (s, 1H), 6.89 (s, lH), 6.96 (s, 1H), 7.33 (m, 10H), 8.13 (d, 1H), 8.36 (@, 1H). (2) 7- [2-Chloromethylene-2- (2-formylaminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid benzhydryl ester (Isomer A) (4.92 g, 0.0069 mol) was dissolved in methylene chloride (60 m#) and cooled to 0 ¯ 50C. With addition of anisole (5 m#), followed by addition of trifluoroacetic acid (25 mQ), the mixture was stirred for 1.5 hours. The reaction mixture was subjected to concentration under reduced pressure, and the residue was charged with ethyl acetate (60 m#) and water (25 mQ) and cooled on ice. The mixture was adjusted to pH 8.30 with a saturated aqueous sodium hydrogen carbonate solution. After extraction, the aqueous layer was separated and extracted again (40 m# x 3) with ethyl acetate. The aqueous layers were separated, ice-cooled and adjusted to pH 2.0 with 2N HCl. The precipitated crystals were collected by filtration, dried on air and dried on potassium hydroxide under reduced pressure to yield 7-[2-chloromethylene-2-(2-formylaminothia- zol-4-yl)acetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid as white powders (Isomer A) (3.40 g, 94%). NMR dppm(d6-DMSO): 3.63 Cm, 2H), 3.89 (s, 3H), 4.26 (m, 2H), 5.13 (d, J=4.5Hz, 1H), 5.76 (dd, J=4.5HZ, 9Hz, 1H), 7.00 (s, 1H), 7.03 (s, 1H), 8.46 (s, 1H), 9.60 (d, J=9Hz, 1H) (3) 7-[2-Chloromethylene-2-(2-formylaminothiazol-4-yl) acetamido]-3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylic acid (Isomer A) (3.40 g, 0.00645 mol) was dissolved in a mixed solvent composed of methanoltetrahydrofuran (100 m#, 1 : 1) and the solution was then ice-cooled. With addition of phosphorus oxychloride (1.98 g, 0.0129 mol), the mixture was stirred for 2 hours. The reaction mixture was charged with water (30 mQ), then adjusted to pH 5 with a saturated aqueous sodium hydrogen carbonate solution. The mixture was concentrated at room temperature under reduced pressure. The residue was icecooled and adjusted to pH 7.5 with a saturated aqueous sodium hydrogen carbonate solution. The resulting mixture was extracted with ethy acetate (40 mt x 2), and the aqueous layers were separated and after ice-cooling adjusted to pH 2.0 with 2N-HCQ. The precipitated crystals were collected by filtration, dried on air and dried on phosphorus pentoxide under reduced pressure to yield 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as white powders (2.3 g, 69%). NMR dppm(d6-DMSO): 3.69 (m, 2H), 3.96 (s, 3H), 4.30 (m, 2N), 5.16 (d, J=4.5Hz, 1H), 5.76 (dd, J=4.5Hz, 7.5Hz, 1H), 6.40 (s, 1H), 6.86 (s, 1H), 7.13 (bs, 2H), 9.56 (d, J=7.5Hz, 1H) (4) To 7-[2-chloromethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(l-methyl-1H-tetrazol-5-yl) i ome thyl- 4cephem- 4-carboxylic acid as white powders (Isomer A) (2.3 g) was added water (15 ml), and the mixture was adjusted under stirring with a saturated aqueous sodium hydrogen carbonate solution to pH 7.1. The solution was purified by passing through XAD-2 column to yield sodium 7-[2-chloromethylene-2 (2-aminothiazol-4-yl)acetamido]-3-(l-methyl-1H-tetrazol-5- yl)thiomethyl-3-cephem-4-carboxylate (Isomer A) as white powders (0.5 g). NMR dppm(d6-DMSO): 3.48 (qAB, J=18Hz, 2H), 3.94 Cs, 3H), 4.34 (qAB, J=12Hz, 2H), 5.02 (d, J=5Hz, 1H), 5.62 (dd, J=5Hz, 8Hz, 1E), 6.42 (s, 1B), 6.84 (s, 1H), 7.14 (bs, 2B), 9.48 (d, J=8Hz, 1H) Elemental analysis for C16H14C#N8O4S3Na 2H2O: Calculated: C, 33.54; H, 3.17; N, 19.56 Found : C, 33.02; H, 3.12; N, 18.94 Example 28 (1) Using 2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A) and 7-aminocephalosporanic acid benzhydryl ester as the starting materials, the reaction was carried out following the procedure of Example 27 - (1) to yield 7-[2-chloromethylene-2-(2-formylaminothiazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid benzhydryl ester. NMR #ppm(CDC#3): 2.0 (s, 3H), 3.50(qAB, J=16.5Hz, 2H), 4.92(qAB, J=12Hz, 2H), 5.13(d, J=4.5Hz, 1H). 6.0 (dd, J=4Hz, 9Hz, 1H), 6.76 (s, 1H), 6.96(s, 1H), 7.05 (s, 1H), 7.33 (m, 10H), 8.20 (d, J=9Hz, 1H), 8.4 (s, 1H) (2) Using 7-[2-chloromethylene-2-(2-formylaminothiyzol-4yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 27 - (2) to yield 7-[2-chloromethylene-2-(2-formylamino- thiazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4carboxylic acid (Isomer A). NMR #ppm(CDC#3): 2.00 (s, 1H), 3.63(m, 2H), 4.83(m, 2H), 5.33(d, J=6Hz, 1H), 5.86 (dd, J=6Hz, 9Hz, 1H), 7.00 (s, 1H), 7.03 (s, 1H), 8.50 (s, 1H), 9.60 (d, J=9Hz, 1H) (3) Using 7-[2-chloromethylene-2-(2-formylaminothazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 27 - (3) to yield 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid (Isomer A). NMR #ppm(CDC#3): 2.03 (s, 3H), 3.66(qAB, J-9Hz, 2H), 4.86(qAB, J=13.5Hz, 2H), 5.07(d, J=3Hz, 1H), 5.92 (dd, J=3Hz, 9Hz, 1H), 6.53 (s, 1H), 6.92 (s, 1H), 8.66 (d, J=9Hz, 1H) (4) Using 7-[2-chlormethylene-2-(2-aminothiazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 27 - (4) to yield sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetomido]-3-acetoxymethyl-3-cephem-4-carboxylate (Isomer A). NMR #ppm(CDC#3): 2.00 (s, 3H), 3.48Cm, 2H), 4.86(d, J=4zz, 1H), 4.94 (qAB, J=12Hz, 2H), 5.76 (dd, J=4Hz, 8Hz), 6.56 (s, 1H), 6.92 (s, 1H), 7.12 (s, 1H), 8.36 (d, J=8Hz, 1H) Elemental analysis for C16H14CZN4O6S2Na: Calculated: C, 39.96; H, 2.93; N, 11.65 Found : C, 38.22; H, 2.95; N, 10.27 Example 29 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(1-carbomylmethyl-1-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP;20 (trade name) to yield sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido] 3-(1-carbamoylmethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylate (Isomer A). IR (KBr): 1760, 1600, 1530 cm 1. NMR #ppm(d6-DMSO): 3.45 (qAB, J=16Hz, 2H), 4.32 (q, J=12Hz, 2H), 5.05 (m, 2H), 5.64 (dd, J=6Hz, J=8Hz, 1H), 6.42 (s, 1H), 6.86 (s, 1H), 7.17 (bs, 2H), 7.49 (bs, 1H), 9.50 (d, J=8Hz, 1H). Elemental analysis for C17H15N9S3O5NaCl.H2O: Calculated: C, 34.14; N, 2.86; N, 21.08 Found : C, 31.91; H, 2.68; N, 19.05. Example 30 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(1-methoxycarbonylmethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield disodium 7-[2-chloro- methylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-methOxy- carbonylmethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem4-carboxylate (Isomer A). IR (KBr): 1750, 1600, 1540 cm NMR dppm(d6-DMSO): 3.50 (qAB, J=16Hz, 2H), 3.78 (s, 3H). 4.36 (qAB, J=13Hz, 2H), 5.07 (d, J=6Hz, 1H), 5.45 Cs, 2H), 5.65 (dd, J=6Hz, 8Hz, lH), 6.44 (s, 1H), 6.88 (s, 1H), 7.17 (bs, 2H), 9.51 (d, J=8Hz, 1H). Elemental analysis for C18H16N8S3O6NaCL: Calculated: C, 36.34; H, 2.71; N, 18.83 Found : C, 32.49; H, 2.45; N, 16.77. Example 31 Using 7-[2-chloromethylene-2-(2-aminothiayol-4-y)acetamido]-3-(1-hydroxyethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 t6 yield sodium 7-[2-chloro- methylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-hydroxyethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylate (Isomer A). IR (KBr): 3450, 1760, 1605 cm NMR dppm(d6-DMSO): 3.78 Ct, J=SHz, 2H), 4.36 cubs, 2H), 5.03 (d, J=7Hz, 1H), 5.61 (dd, J=7Hz, J=8Hz, 1H), 6.42 (s, 1H), 6.85 Cs, 1H), 7.13 cubs, 2H), 9.47 (d, J=8Hz, 1H). Elemental analysis for C17H16C#N8O5S3Na: Calculated: C, 35.57; H, 2.81; N, 19.52 Found : C, 30.43; H, 3.18; N, 12.69. Example 32 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido] -3- Cl-cyanomethyl-1, 2,3, 4-tetrazol-5-yl) thiomethyl- 3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield sodium 7-[2-chloromethy- lene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-cyanomethyl- 1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A). NMR dppm(d6-DMSO): 3.48 (qAB, J=20Hz, 2H), 4.36 (qAB, J=14Hz, 2H), 5.04 (d, J=SNz, lH), 5.37 (s, 2H), 5.64 (dd, J=5Hz, 8Hz, 1H), 6.43 (s, 1H), 6.85 (s, 1H), 7.14 (bs, 2H), 9.48 (d, J=8Hz, 1H). Elemental analysis for C17H13N9S3O4naCl.3H2O: Calculated : C, 33.15; H, 3.11; N, 20.46 Found : C, 32.44; H, 2.84; N, 16.59. Example 33 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(1,2,3-thiadiazol-5-yl)thiomethyl-3-cephem-4carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield sodium 7-[2-chloromethylene-2- (2-aminothiazol-4-yl)acetamidol-3-(1,2,3-thiadiazol- 5-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A). IR (KBr): 1760, 1600, 1530 cm MR #ppm(d6-DMSO): 3.44 (qAB, J=16Hz, 2H), 4.46 (bs, 2H), 5.06 (d, J=5Hz, 1H), 5.61 (dd, J=5Hz, 8Hz, 1H), 6.43 (s, 1H), 6.85 (s, 1H), 7.16 (bs, 1H), 9.07 (s, 1H), 9.52 (d, J=8Hz, 1H). Elemental analysis for C16H12N6S4O4NaCl.2H2O: Calculated: C, 33.42; H, 2.81; N, 14.62 Found : C, 31.86; H, 2.61; N, 13.71. Example 34 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(1,2,3-triazol-5-yl)thiomethyl-3-cephem-4carboxylic acid Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield sodium 7[2-chloromethylene-2-(2- aminothiazol-4-yl)acetamido]-3-(1,2,3-triazol-5-yl)thriomethyl-3-cephem-4-carboxylate (Isomer A). NMR 6ppmCd6-DMSO): 3.49 (qAB, J=12Hz, 2H), 4.07 (qAB, J=14Hz, 2H), 5.06 (d, J=SHz, 1H), 5.61 (dd, J=SHz, 8Hz, 1H), 6.40 (s, 1H), 6.82 (s, 1H), 7.13 (bs, 2H), 7.52 (s, 1H), 9.53 (d, J=8Hz, 1H). Elemental analysis for C16H13N6S3O4NaCl.2H O: Calculated: C, 35.33; H, 3.15; N, 15.45 Found : C, 32.45; N, 3.04; N, 15.53. Example 35 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(2-hydroxycarbonylmethylthio-1,3,4-thiadiyzol5-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield sodium 7-[2-chlormethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(2-hydroxycarbonylmethylthio-1,3,4-thiadia- zol-5-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A). IR (KBr): 1760, 1600 cm NMR #ppm(d6-DMSO): 3.49 (qAB, J=28Hz, 2H), 3.72 (s, 2H), 4.47 (qAB, J=12Hz, 2H), 5.07 (d, J=SHz, 1H), 5.63 (dd, J=5Hz, 8Hz, 1H), 6.43 (s, 1H), 6.86 (s, 1H), 7.15 (bs, 2H), 9.53 (d, J=8Hz, 1H). Elemental analysis for C8H13N6S5O6Na2Cl-4H2O: Calculated: C, 29.90; H, 2.93; N, 11.62 Found : C, 28.88; H, 2.65; N, 10.88. Example 36 Using 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet- amido]-3-(2,5-dihydro-2-methyl-5-oxo-as-triazine-3-yl) thiomethyl-3-cephem-4-carboxylic acid Isomer A) as the starting material, the reaction was carried out following the procedure of Example 1 - (3) and the resulting product was purified by Diaion HP-20 to yield sodiun 7-[2-chrolo- methylene-2-(2-aminothiazol-4-yl)acetamido]-3-(2-dihydro2-methyl-5-oxo-as-triazine-3-yl)thiomethyl-3-cephem-4carboxylate (Isomer A). IR (KBr): 1760, 1610 cm NMR dppm(d6-DMSO): 3.69 (bs, 2H), 4.27 (qAB, J-12Hz, 2H), 5.03 (d, J=7Hz, 1H), 5.69 (dd, J=7Hz, J=8Hz, 1H), 6.42 (s, 1H), 6.84 (s, 1H), 7.12 (bs, 2H), 7.61 (s, 1H), 9.55 (d, J=8Hz, 1H). Elemental analysis for C18H15ClN7O5S3Na: Calculated: C, 38.33; H, 2.68; N, 17.38 Found : C, 32.19, H, 3.12; N, 12.82; Synthesis Example 11 (1) After 2.42 g of ethyl 2-formyl-2-(2-formylaminothiazol-4-yl)acetate was suspended in 50 mQ of dried methylene chloride, there was added dropwise 1.21 mQ of pyridine and dissolved under ice-cooling. To the solution, there was added 3.93 g of triphenylphosphine, and then, 3.81 g of iodine was gradually added thereto. The resulting mixture was stirred under ice-cooling for 15 minutes, and further stirred at room temperature for 20 minutes. After completion of the reaction, 1 mL of methanol was added to the mixture and then 150 mQ of ethyl acetate was added. Then, the mixture was washed successively with water, a 5% aqueous sodium thiosulfate solution, water and a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure, purification by column chromatography yielded 0.85 g of ethyl 2-iodomethylene-2-(2formylaminothiazol-4-yl)acetate (Isomer B) as colorless crystals. Ethyl 2-iodomethylene-2-(2-formylaminothiazol-4-yl)- acetate (Isomer B): IR (KBr): 1700, 1685, 1560 cm-l NMR dppm(d6-DMSO): 1.23 (t, J=7Hz, 3H), 4.18 (q, J=7Hz, 2H), 7.37 (s, 1H), 8.21 Cs, 1H), 8.52 Cs, 1H), 12.3 (bs, 1H). (2) After 5.0 g of ethyl 2-formyl-2-(2-formylamino- thiazol-4-yl)acetate was suspended in 75 mQ of dried methylene chloride, 3.43 g of potassium carbonate was added to the suspension udner ice-cooling, and the mixture was stirred for 1 hour. Then, 25 mQ of dried methylene chloride dissolved 5.32 g of o-nitrobenzenesulfonylchloride therein was added dropwise to the mixture, and the resulting mixture was stirred at room temperature for 18 hours. After completion of the reaction, methylene chloride was removed by distillation under reduced pressure, and ethyl acetate was added thereto. The reaction mixture was washed with water and then with a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure, purification by column chromatography, and recrystallization from benzene yielded 6.13 g of 2 (o-nitrobenzenesulfonyloxymethylene)-2-(2-formylaminothiazol-4-yl)acetic acid as colorless crystals. 2- (o-Nitrobenzenesulfonyloxymethylene) -2- (2-formylamino- thiazol-4-yl)acetic acid: IR (KBr): 1710, 1690, 1630, 1535 cm 1. NMR dppm(d6-DMSO): 1.23 (t, J=7Hz, 3H), 4.19 (q, J=7Nz, 2H), 7.29 (s, 1H), 7.74 (s, 1H), 7.9 X 8.4 (m, 4H), 8.48 (s, 1H), 12.3 (bs, 1H). (3) 2-(o-Nitrobenzenesulfonyloxymethylene)-2-(2-formylaminothiazol-4-yl)acetic acid (4.27 g) was dissolved in 50 mQ of dried methylene chloride. Subsequently, after 6.38 g of triethylbenzylammoniumiodide and 0.25 g of boron trifluoride ethyl etherate were added to the solution, the mixture was stirred for 15 hours. The solvent in the mixture was removed by evaporation under reduced pressure, and 150 mQ of ethylraceta-te-was added thereto. The mixture was washed successively with water, a 5% aqueous sodium thiosulfate solution, water and a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure yielded 2.69 g of ethyl 2-iodomethylene-2-(2-formylaminothiazol4-yl)acetate (Isomer B) as colorless crystals. (4) Ethyl 2-iodomethylene-2-(2-formylaminothiazol-4-yl)- acetate (2.0 g) (Isomer B) was dissolved in 20 mQ of dried ethyl acetate, and the mixture was stirred under high-pressure marcury lamp (400 W) irradiation for 5.5 hours (The ratio of Isomer A : B is 1 : 2 from integral ratio of NMR proton). After the reaction mixture was concentrated, the residue was purified by column chromatography to obtain 520 mg of ethyl 2-iodomethylene-2 (2-formylaminothiazol-4-yl)acetate (Isomer A) as colorless crystals. And at the same time, 1.02 g of Isomer B which has been used as the starting material was obtained. Ethyl 2-iodomethylene-2-(2-formylaminothiazol-4-yl)acetate (Isomer A): IR (KBr): 1700, 1690, 1530 cm 1 NMR 6ppm(d6-DMSO): 1.33 (t, J=7Hz, 3u), 4.33 (q, J=7Hz, 2H), 7.24 (8, 1H), 7.51 (s, 1H), 8.49 (s, 1H), 12.3 (bs, 1H). (5) Ethyl 2-iodomethylene-2-(2-formylaminothiyzol-4-yl)acetate (457 mg) (Isomer A) was added a 3% aqueous potassium hydroxide solution under ice-cooling, and the mxiture was stirred at the same temperature for 8.5 hours. After completion of the reaction, the mixture was adjusted to pH 7.0 with a 10% aqueous phosphoric acid solution, and washed with ethyl acetate. Then, the organic solvent in the aqueous layer was removed by distillation under reduced pressure, the mixture was adjusted to pH 2.3 with a 10% aqueous phosphoric acid solution. The precipitated crystals were collected by filtration, washed with water and dried to obtain 387 mg of 2-iodomethylene2-(2-formylaminothiazol-4-yl)acetic acid (Isomer A) as colorless crystals. 2-Iodomethylene-2-t2-formylaminothiazol-4-yl)acetic acid (Isomer A): IR (KBr): 1700, 1670, 1640, 1555 cm-1 NMR dppm(d6-DMSO): 7.27 Cs, 1H). 7.37 (s, 1H), 8.50 Cs, 1H), 12.3 (bs, 1H) Example 37 (1) After 340 mg of 2-iodomethylene-2-(2-formylamino- thiazol-4-yl)acetic acid (Isomer A) and 476 mg of 7amino-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4carboxylic acid benzohydryl ester were suspended in 5 m# of THF, 255 mg of dicyclohexylcarbodiimido was added to the suspension, and the mixture was stirred at room temperature for 2 hours. After the reaction mixture was filtrated, the resulting filtrate was concentrated' and the residue was purified by column chromatography to obtain 650 mg of 7-[2-iodomethylene-2-(2-formylamino- thiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A as pale yellow amorphous crystals. 7-t2-Iodomethylene-2-(2-formylaminothiazol-4-yl)acet- amido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4carboxylic acid benzhydryl ester (Isomer A): IR (KBr): 1775, 1770, 1665 cm NMR dppm(d6-DMSO): 3.76 (bs, 2H), 4.24 (d, J=14Hz, 1H), 4.53 Cd, J=14Hz, 1H), 5.28 (d, J=SHz, 1H), 5.93 (dd, J=SHz, 8Hz, 1H), 6.93 (s, 1H), 7.09 (s, 1H), 7.33 (m, llH), 8.50 (s, 1H), 9.46 (s, 1H), 9.58 (d, J=8Hz, 1H), 12.3 (bs, 1H). (2) After 7-[2-iodomethylene-2-(2-formylaminothiazol-4yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3cephem-4-carboxylic acid benzhydryl ester (Isomer A) (530 mg) was suspended in 5 mQ of absolute methanol, 0.24 mQ of phosphrus oxychloride was added dropwise to the suspension under ice-cooling, and then the mixture was stirred at room temperature for 1 hour. To the resulting mixture, there were added 30 m & of ethyl acetate and 10 m & of a saturated aqueous sodium hydrogen carbonate. Subsequently, the reaction mixture was separated, and then the aqueous layer was extracted twice with 10 mA of ethyl acetate. The ethyl acetate layer was combined, washed with water and then with a saturated saline solution, and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure and purification by column chromatography yielded 380 mg of 7-[2-iodomethy- lene-2- (2-aminothiazol-4-yl) acetamido}l-(1,3,4-thiadia- zol-2-yl) thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A) as pale yellow amorphous crystals. 7- t2-Iodomethylene-2-(2-aminothiazol-4-yl)acetamido]-3- (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid benzhydryl ester (Isomer A): IR (KBr): 1770, 1715, 1660, 1610, 1520 cm 1. NMR #ppm(d6-DMSO): 3.75 (bs, 2H), 4.23 (d, J=14Hz, 1H), 4.52 (d, J=14Hz, 1H), 5.26 (d, J=SHz, 1H), 5.88 (dd, J=SHz, 8Hz, 1H), 6.47 (s, 1H), 6.93 (s, 1H), 7.11 (s, 1H), 6.40 (m, 12H), 9.48 (s, 1H), 9.53 (d, J=8Hz, 1H). (3) After 7-[2-iodomethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem4-carboxylic acid benzhydryl ester (Isomer A) (310 mg) was dissolved in 0.6 m# of dried methylene chloride and 0.3 mQ of anisole, 0.6 mQ of trifluoroacetic acid was added dropwise to the solution under ice-cooling, and the mixture was stirred at the same temperature for 1 hour. After completion of the reaction, 5 mQ of ethyl acetate was added to the mixture, and under ice-cooling, the mixture was adjusted to pH 8.0 with a saturated aqueous sodium hydrogen carbonate solution. After the resulting mixture was separated, the aqueous layer was adjusted to pH 6.5 with 1N hydrochloric acid and treated with activated charcoal. After filtration of the mixture, the filtrate was adjusted to pH 2.7 with 1N hydrochloric acid under ice-cooling, and stirred for 1 hour. The precipitated crystals were collected by filtration, washed with water and dried to obtain 136 mg of 7-[2iodomethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1,3,4thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A). 7-[2-Ìodomethylene-2-(2-aminothiazol-4-yl)acetamido]-3- (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (Isomer A): IR (KBr): 1765, 1655, 1630, 1525 cam 1 NMR dppm(d6-DMSO): 3.61 (d, J=17Hz, 1H), 3.79 (d, J=17Hz, 1H), 4.29 (d, J=13Hz, 1H), 4.62 (d, J-13Hz, 1H), 5.21 Cd, J=5Hz, 1H), 5.80 (dd, J=5Hz, 8Hz, 1H), 6.42 (s, 1H), 7.08 (s, 1E), 9.53 (d, J=8Hz, 1H), 9.57 (s, 1H). Example 38 2-Chloromethylene-2-(2-aminothiazol-4-yl)acetic acid (Isomer A) (2.04 g) was suspended in 20 mQ of ethyl acetate, and the suspension was cooled to -300C and added dropwise the Vilsmeyer's reagent (prepared by 3.06 g of phosphorus oxychloride was added to 1.46 g of DMF under ice-cooling, and then the mixture was stirred at 500C for 30 minutes and thereafter 30 mQ of THF was added thereto). The reaction mixture was stirred at the same temperature for 5 minutes, then dissolved by raising the temperature at -5ec. On the other hand, 2,16 g of 6-aminopenicillanic acid was suspended in 50 mL of water, and 2.1 g of sodium hydrogen carbonate was added thereto and dissolved. Then, 50 mt of THF was added to the solution. To the solution was added dropwise, under ice-cooling, the above-mentioned solution while adjusting the pH of the former solution to 7.5 X 8.5, followed by stirring at the same temperature for 1 hour. Ethyl acetate and THF were removed by distillation under reduced pressure, the reaction mixture was adjusted to pH 7, washed with ethyl acetate and adjusted to pH 3 to yield precipitated crystals. The crystals were dissolved in an aqueous sodium hydrogen carbonate solution, and then the solution was purified by HP-20 to obtain 0.41 g of sodium 6-(2-chloromethylene-2-(2-amino- thiazol-4-yl)acetamido]penicillanate (Isomer A) as yellowish brown amorphous crystals. Sodium 6-[2-chloromethylene-2-(2-aminothiazol-4-yl)acet amido] penicillanate (Isomer A): IR (RBr): 1760, 1640 cm 1. NMR dppm(d6-DMSO): 1.51 (s, 3H), 1.56 (s, 3H), 3.97 (s, lH), 5.53 (bs, 2H), 6.43. (s, 1H), 6.82 (s, lH), 7.14 (bs, 2H), 9.19 (d, J8Hz, 1H). Synthesis Example 12 Potassium t-butoxide (3.36 g, 30 mmol) was suspended in dioxane (80.m#) under argon atmosphere. To the resulting mixture, there was added chloromethyltriphenylphosphonium iodide (10.96 g, 25 nunol) under ice-cooling. The mixture was stirred for 20 minutes, and stirring was further continued for 3 hours at room temperature. After ethyl 2 oxo-2- (2-t-butaxycarbonylaminothiazol-4-yl) acetate (3.0 g, 10 mmol) was added to the resulting mixture under ice water-cooling, the mixture was stirred for 10 minutes, and stirring was further continued for 2 hours at room temperature. Insolubles-were removed by filtration, and the filtrate was washed with a saline solution. The filtrate was dried over anhydrous magnesium sulfate, and evaporated the solvent. The residue was purified by silica gel column chromatography (eluent; n-hexane ethyl acetate = 10 : 3) to obtain ethyl 2-chloromethylene-2-(2-butoxycabonylaminothiazol-4-yl)acetate (2.7 g, 81%). The ratio of Isomer A and B was 7 : 3. NMR #ppm (CDC#3): Isomer A: 1.38 (t, J-7Nz, 3H), 1.50 (s, 9H), 4.42 (q, J=7Hz, 2H), 6.90 Cs, 1X), 7.13 (s, 1H), 9.30 (s, 1H). Isomer B: 1.20 (t, J=7Hz, 3N), 1.53 (s, 9H), 4.17 (q. J=7Hz, 2H), 7.10 (s, 1H), 7.46 (s, 1H), 9.33 (s, 1H). Synthesis Example 13 . (1) Phosphorus oxychloride (.68.9 g, 0.45 mol) was added dropwise to DMF (32.85 g, 0.45 mol) under ice-cooling. After. the dropwise addition, the mixture was stirred for 30 minutes and then added chloroform (50 mQ). To the suspension of ethyl 2-formyl-2-(2-formylaminothiazol-4- yl)acetate (45.1 g, 0.18 mol) in chloroform (250 mi), there was added dropwise the previously prepared mixture. After the dropwise addition, the mixture was stirred for 3 hours and then ice-cooled. The mixture was adjusted to ,pH 7 by adding an aqueous sodium hydroxide solution and extracted with chloroform. The extract was dried over magnesium sulfate and evaporated the solvent to obtain ethyl 2-chloromethylene-2- (2-dimethylaminomethyleneaminothiazol-4-yl)acetate (Isomer B) (59.7 g). IR (oil): 1710, 1610 cm 1. NMR dppm(CDCt3): 1.30 (t, Js7Hz, 3H), 3.10 (s, 6H), 4.26 (q, J=7Hz, 2H), 7.00 (s, lR), 7.50 (s, 1H), 8.30 (s, 1H). Mass m/e (%): 289 (21), 288 (9), 287 (53), 252 (56), 206 (44), 152 (10(1), 151 (22). (2) To ethyl 2-chloromethylene-2-(2-dimethylamino methyleneaminothiazol-4-yl)acetate (Isomer B) (59.7 g) was added a mixed anhydride of formic acid and acetic acid (68.5 m#) under ice-cooling, and the mixture was stirred at room temperature for 3 hours. After 400 mQ of water was added thereto, the mixture was concentrated under reduced pressure. The concentrates were extracted with ethyl acetate. The extract was washed with an aqueous sodium hydrogen carbonate solution and then with water, and dried over magnesium sulfate. Evaporation of the solvent yielded yellow crystals. Recrystallization from ethyl acetate yielded ethyl 2-chloromethylene-2 (2-formylaminothiazol-4-yl)acetate (Isomer B) (28.8 g, 53% through ethyl 2-formyl-2-(2-formylaminothiazol-4-yl)acetate . Melting point: 99 # 1000C. IR (KBr): 1710, 1695, 1565, 1290, 1260 cm-1. NMR #ppm(CDc#3): 1.26 (t, J=7Hz, 3H), 4.20 (q, J=7Hz, 2H), 7.14 (s, 1H), 7.60 (s, 1H), 8.48 (s, 1H), 12.22 (bs, 1H). Mass m/e (%): 260 (M+, 16), 234 (21), 232 (58), 186 (24), 151 (100). Elemental analysis for C9H9C#N2=3S: Calculated: C, 41.46; H, 3.48; N, 10.75 Found : C, 41.55; H, 3.42; N, 10.80. (3) Ethyl 2-chloromethylene-2-(2-formylaminothiazol-4yl)acetate (Isomer B) (0.1 g) was adjusted to pH 1 by adding concentrated hydrochloric acid. The resulting mixture was stirred at 70 C under heating for 7 hours. The mixture was cooled and then neutralized with 1N sodium hydroxide. The reaction mixture was extracted with ethyl acetate (25 mQ). The extract was washed with water and dried over magnesium sulfate. Evaporation of the solvent yielded brownish oily product (0.1 g). This product was turned out to be the mixture of ethyl 2chloromethylene-2-(2-aminothiazol-4-yl)acetate. The ratio of Isomer A and B is 1 : 2.7 by the use of NMR spectrum. Isomer A Mass m/e (%): 234 (41), 232 (100), 197 (67), 151 (94), 125 (92). NMR #ppm(CDC#3): 1.33 (t, J=7Hz, 3H), 4.38 (q, J=7Hz, 2H), 5.67 (bs, 2H), 6.47 (s, 1H), 7.07 (s, 1H). Isomer B Melting point: 65CC. IR (KBr): 3450, 3300, 3170, 3000, 1700, 1635, 1605, 1540, 1250cm-1. NMR #ppm(CDC#3): 1.33 (t, J=7Hz, 3H), 4.30 (q, J=7Hz, 2H), 5.73 (bs, 2H), 6.77 (s, 1H), 7.49 (s, 1H). Mass m/e(%): 234 (40), 232 (100), 197 (66), 169 (30), 151 (98), 125 (97). (4) Ethyl 2-chloromethylene-2-(2-formylaminothiaazol-4yl)acetate (Isomer B) (3.5 g, 0.015 mol) was dissolved in acetone (70 mQ), and the solution was stirred for 15 hours under high-pressure marcury lamp (400 W) irradiation (the ratio of Isomer A : B is 1 : 2 by integral ratio of NMR proton). Evaporation of the solvent under reduced pressure yielded white crystals. Purification by column chromatography afforded ethyl 2-chloromethylene-2-(2-formylaminothiazol4-yl)acetate (Isomer A) (0.89 g, 25%). And at the same time, there were obtained Isomer B (2.08 g, 59%) which has been used as the starting material and the mixture of Isomer A and Isomer B (0.50 g, 14%). Physical properties and spectrum data of the above-obtained ethyl 2-chloro methylene-2-(2-formylaminothiazol-4-yl)acetate (Isomer A) are as follows. Melting point: 139 N 1420C. NMR dppm(CDCQ3): 1.36 (t, J=7Hz, 3H), 4.34 (q, J=7Hz, 2H), 6.96 (s, 1H), 7.20 (s, lN), 8.50 (s, 1H), 9.96 (bs, 1H). Elemental analysis for C9H9C#N2O3S: Calculated: C, 41.46; H, 3.48; N, 10.75 Found : C, 42.13; H, 3.63; N, 10.35. Test Example Antibacterial activities of the compounds according to this invention, which had been prepared in the preceding Examples, were measured according to the method prescribed by The Committee of Amendment of "The method for measurement of the minimum inhibition concentration", The Chemotherapy Association, Japan (See Chemotherapy, Vol. 29, No. 1, pp. 76 X 79 (1981)). The test results are shown in terms of the minimum inhibition concentration (MIC) (unit: pg/mQ) in the following Tables 1 to 4. Table 1 (MIC) EMI106.1 <tb> anina <tb> <SEP> \ <SEP> (sbxin) <SEP> Staphy <SEP> ZOCOCCUJ <SEP> SaZmon8ZZa <SEP> Proteus <tb> <SEP> (stain) <SEP> Staphylococcus <SEP> Salmonella <SEP> Proteus <tb> No. <SEP> aureus <SEP> IID-971 <SEP> IFO <SEP> 3848 <tb> No. <SEP> X <SEP> . <tb> <SEP> 1 <SEP> 0.10 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 2 <SEP> 6.25 <SEP> 0.0125 <SEP> 0.0125 <tb> <SEP> 3 <SEP> 0.10 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 4 <SEP> 0.78 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 5 <SEP> 0.05 <SEP> 0.78 <SEP> 0.78 <tb> <SEP> 6 <SEP> 0.78 <SEP> 1.56 <SEP> 6.25 <tb> <SEP> 7 <SEP> 0.39 <SEP> 1.56 <SEP> 1.56 <tb> <SEP> 8 <SEP> 0.78 <SEP> 25 <tb> <SEP> 9 <SEP> 3.125 <SEP> 25 <tb> <SEP> 10 <SEP> 1.56 <SEP> < <SEP> 0.006 <SEP> L <SEP> 0.006 <tb> <SEP> 11 <SEP> 0.78 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 12 <SEP> 1.56 <SEP> < <SEP> 0.006 <SEP> i <SEP> < <SEP> 0.006 <tb> <SEP> 13 <SEP> 50 <SEP> -25 <SEP> i <SEP> 50 <tb> <SEP> 14 <SEP> 100 <SEP> I <SEP> 0.39 <SEP> 0.39 <tb> <SEP> 15 <SEP> 1.56 <SEP> 0.05 <SEP> 0.39 <tb> <SEP> 16 <SEP> 0.78 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 17 <SEP> 3.125 <SEP> 0.0125 <SEP> < <SEP> 0.006 <tb> <SEP> 18 <SEP> 12.5 <SEP> 0.10 <SEP> < <SEP> 0.006 <tb> <SEP> 19 <SEP> 1.56 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 20 <SEP> 0.10 <SEP> < <SEP> 0.006 <SEP> < <SEP> 0.006 <tb> <SEP> 21 <SEP> 0.2 <SEP> < <SEP> 0.006 <SEP> 0.0125 <tb> table 2 (MIC) EMI107.1 <tb> <SEP> Strain <SEP> Staphylococcus <SEP> E8cherichia <SEP> Proteus <SEP> Pseudomonas <tb> <SEP> aureus <SEP> coti <SEP> morganii <SEP> I <SEP> aeruginosa <tb> Ex <tb> Ole <SEP> FDA <SEP> 209 <SEP> PJC-1 <SEP> NIBJ-JC-2 <SEP> IFO-3848 <SEP> NCTC <SEP> 10490 <tb> <SEP> 22 <SEP> 0.2 <SEP> 0.2 <SEP> < 0.0063 <SEP> 1.56 <tb> <SEP> 25 <SEP> 0.2 <SEP> 0.1 <SEP> < 0.0063 <SEP> 0.20 <tb> <SEP> 26 <SEP> 0.39 <SEP> 0.1 <SEP> < 0.0063 <SEP> 0.39 <tb> Table 3 (MIC) EMI108.1 Strain <SEP> Staphylococcus <SEP> Eacheriohia <SEP> Klebaiella <SEP> Salmonella <SEP> Proteus <tb> <SEP> aureus <SEP> coli <SEP> pneumoniae <SEP> typhimurium <SEP> mirabilis <tb> Example <SEP> No. <SEP> Fda <SEP> 209 <SEP> PJC-1 <SEP> NIHJ-JC-2 <SEP> PCI-602 <SEP> IID-971 <SEP> IFO <SEP> 3849 <tb> 27 <SEP> 0.78 <SEP> 0.20 <SEP> < 0.00625 <SEP> 0.78 <SEP> 0.20 <tb> 28 <SEP> 12.5 <SEP> 0.10 <SEP> 0.05 <SEP> 12.5 <SEP> 0.20 <tb> Table 4 (MIC) EMI109.1 slf <SEP> in <SEP> Staphy <SEP> tococcus <SEP> Srr <SEP> tmons <SEP> I <SEP> ta <SEP> Proteus <tb> <SEP> (rurous <SEP> typhmrium <SEP> morganii <tb> uaple <SEP> : <SEP> MS <SEP> 353 <SEP> 901 <SEP> IFO <SEP> 3848 <tb> <SEP> 29 <SEP> 0.78 <SEP> 0.10 <tb> amp <tb> <SEP> 29 <SEP> 0.78 <SEP> 0.10 <SEP> ¯ <tb> <SEP> 30 <SEP> 0.78 <SEP> 0.20 <tb> <SEP> 31 <SEP> 0.78 <SEP> 0.39 <SEP> < 0.00625 <tb> <SEP> 32 <SEP> 1.56 <SEP> 0.78 <SEP> 0.0125 <tb> <SEP> 33 <SEP> 0.10 <SEP> 0.20 <SEP> < 0.00625 <tb> <SEP> 34 <SEP> 0.78 <SEP> 0.78 <SEP> 0.0125 <tb> <SEP> 35 <SEP> 0.78 <SEP> 0.78 <SEP> < 0.00625 <tb> <SEP> 36 <SEP> 0.39 <SEP> 0.39 <SEP> < 0.00625 <tb> <SEP> 37 <SEP> 0.20 <SEP> 0.39 <SEP> < 0.00313 <tb> <SEP> 38 <SEP> 0.20 <SEP> 3.125 <SEP> 0.05 <tb>

Claims: Claims: 1. A compound having the following formula: EMI110.1 in which R1 denotes a substituted or unsubstituted thiazolyl radical, a substituted or unsubstituted thiazolylmercapto radical or a substituted or unsubstituted phenyl radical; R2 denotes a halogen atom, a cyano radical, a carbamoyl radical, a lower alkylmercapto radical or an O-lower-alkylcarboxyimidoyl radical; and Y represents group EMI110.2 (wherein R3 denotes hydrogen, a salt forming cation or a protective group for a carboxylic acid, and R4 denotes hydrogen or a residue of a nucleophilic compound). 2. A compound according to Claim 1, wherein the compound represented by the formula: EMI110.3 in which R denotes hydrogen or a protective group for an amino radical, and ? has the same meaning as in Claim 1, which has (Z)-Isomer structure. 3. A compound according to Claim 1, wherein the compound having the formula: EMI111.1 in which R1, R2, R3, R4 and Y have the same meanings as in Claim 1. 4.. A compound according to Claim 1, wherein said substituent of R1 is at least one radical selected from the group consisting of an amino radical, a protected amino radical, a halogen atom, a nitro radical, a cyano radical, a hydroxy radical, a lower-alkyl radical, a lower-alkoxy radical and a lower-alkylmercapto radical. 5. A compound according to Claim 1, wherein the compound is selected from the group consisting of sodium 7- [2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido] -3- C2-methyl-1, 3, 4-thiadiazol-5-yl) thiomethyl- 3-cephem-4-carboxylate (Isomer A), sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido]-desacetoxycephalosporanate (Isomer A), sodium 7- [2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido3-3-(1,3,4-thiadiazol-5-yl) thiomethyl-3-cephem 4-carboxylate (Isomer A), disodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl) acetamido]-3-(2,5-dihydro-6-hydrOxy-2-methyl-5-oXo-as- triazin-3-yl) thiomethyl-3-cepem-4-carboxylate (Isomer A), 7- (2-chloromethylenephenylacetamido) -3-Cl-methyl-iN- tetrazol-5-yl) thiomethyl -3-cephem-4-carboxylic acid (Isomer B), sodium 7-[2-chloromethylane-3-(2-aminothiazol-5-yl)mercaptoacetamido]-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl3-cephem-4-carboxylate, 7-[2-ethylmercaptomethylene-2-(2-aminothiazol-4-yl)acetamido] -3-(1-methyl-lH-tetrazol-5-yl) thiomethyl-3cephem-4-carboxylic acid (Isomer A and B), 7-12-methylmercaptomethylene-2-(2-aminothiazol-4-yl) - acetamido]-3-(1-methyl-lH-tetrazol-5-yl) thiomethyl-3- cephem-4-carboxylic acid (Isomer A and B), 7- [2-cyanomethylene-2- (2-aminothiazol-4-yl) acetamido] -3 (l-methyl-lH-tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid (Isomer A), 7- [2- (o-methylcarboxyimidoylmethylene) -2-(2-aminothiazol- 4-yl) acetamido] -3- (l-methyl-lH-tetrazol-5-yl) thiomethyl- 3-cephem-4-carboxylic acid, 7[2-carbamoylmethylene-2-(2-aminothiazol-4-yl)acetamido]3-(1-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4carboxylic acid, 7- 12-chloromethylene-2-(2-aminothiazol-4-yl)acetamido] -3- (2-methylthio-1,3,4-thiadiazol-5-yl)thiomethyl-3-cephem4-carboxylic acid (Isomer A), 7-l2-bromomethylene-2-(2-aminothiazol-4-yl)acetamido] -3- (l-methyl-lH-tetrazol-5-yl)thiomethyl-3-cephem-4 carboxylic acid, 7- [2-chloromethylene-2- (2-aminothiazol-4-yl) acetamido] cephalosporanic acid l-oxoisobenzofuran-3-yl ester Isomer A), 7- [2-chloromethylene-2-(2-aminothiazol-4-yl) acetamido] cephalosporanic acid pivaloyloxymethyl ester (Isomer A), 7-[2-bromomethylene-2-(2-aminothiazol-4-yl)acetamido]-3 (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid, 7-[2-bromomethylene-2-(2-aminothiazol-4-yl)acetamidol]-3 (2-methyl-1,3,4-thiadiazol-5-yl) thiomethyl-3-cephem-4carboxylic acid, sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl) acetamido] -3- (1-methyl-lH-tetrazol-5-yl)thiomethyl-3- cephem-4-carboxylate (Isomer A), sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3-acetoxymethyl-3-cephem-4-carboxylate (Isomer A), sodium 7- [2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido] -3-(1-carbamoylmethyl-1,2,3,4-tetrazol-5-yl) - thiomethyl-3-cephem-4-carboxylate (Isomer A), disodium 7-[2-chloromethylene-2-(2-aminothtiazol-4-yl) acetamido]-3-(1-methoxycarbonylmethyl-1,2,3,4-tetrazol- 5-yl) thiomethyl-3-cephem-4-carboxylate (Isomer A), sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl)acetamido]-3-(1-hydroxyethyl-1,2,3,4-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylatc (Isomer A), sodium 7- [2-chloromcthylene-2- (2-aminothiazol-4-yl) acetamido] -3-(1-cyanomethyl-1,2,3,4-tetrazol-5-yl) - thiomethyl-3-cephem-4-carboxylate (Isomer A), sodium 7-[2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido] -3-(1,2,3-thiadiazÏl-5-yl) thiomethyl-3-cephem- 4-carboxylate (Isomer A), sodium 7- [2-chloromethylene-2-(2-aminothiazol-4-yl) - acetamido]-3-(1,2,3-triazol-5-yl)thiomethyl-3-cephem-4carboxylate (Isomer A), disodium 7- [2-chloromethylene-2- (2-aminothiazol-4-yl) acetamido]-3-(2-hydroxycarbonylmethylthio-1,3,4-thiadiazol5-yl) thiomethyl-3-cephem-4-carboxylate (.Isomer A), sodium 7- [2-chloromethylene-2- (2-aminothiazol-4-yl) - acetamido]-3-(2,5-dihydro-2-methyl-5-oxo-as-triazine-3-yl)thiomethyl-3-cephem-4-carboxylate (Isomer A), 7-[2-iodomethylene-2-(2-aminothiazol-4-yl) acetamido] -3 (1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid Isomer A), and sodium 6-12-chloromethylene-2- (2-aminothiazol-4-yl) acetamide]penicillanate Isomer A). 6. A process for the preparation of a compound having the formula: EMI114.1 in which R1 denotes a substituted or unsubstituted thiazolyl radical, a substituted or unsubstituted thiazolylmercapto radical or a substituted or unsubstituted phenyl radical; R2 denotes a halogen atom, a cyano radical, a carbamoyl radical, a loweralkylmercapto radical or an O-lower-alkylcarbo xyimidoyl radical; and Y represents a group EMI115.1 (wherein R3 denotes hydrogen, a salt forming cation or a protective group for a carboxylic acid, and R4 denotes hydrogen or a residue of a nucleophilic compound) which comprises reacting a compound having the formula: EMI115.2 wherein Y has the same meaning as defined above, a reactive derivative thereof with respect to the amino radical or a salt thereof, with an acid having the formula: EMI115.3 wherein R1 and R2 have the same meanings as defined above, a reactive derivative thereof with respect to the carboxyl radical or a salt thereof. 7. A process according to Claim 6, wherein the reaction is carried out in the presence of a dehydration agent or a condensing agent when the acid is reacted in the form of a free acid. 8. A process according to Claim 6, wherein said reactive derivative of the acid is an acid chloride, an acid anhydride, a mixed acid anhydride, an active acid amide, an acid cyanide, an active ester or an acid azide. 9. A process according to Claim 6, wherein the reaction is carried out in the presence of a solvent with cooling or at room temperature. 10. A compound having the formula: EMI116.1 wherein R denotes hydrogen or a protective group of amino radical, and R5 denotes an alkyl radical or an aryl radical. 11. A compound according to Claim 10, wherein said protective group of amino radical is selected from the group consisting of a formyl radical, an acetyl radical, a chloroacetyl radical, a trifluoroacetyl radical, a tbutoxycarbonyl radical, a trityl radical and trialkylsilyl radical. 12. A compound according to Claim 10, wherein said alkyl radical or aryl radical of R5 is selected from the group consisting of methyl radical, ethyl radical, t-butyl radical, benzyl radical, trichloroethyl radical, diphenylmethyl radical, phenyl radical and trialkylsilyl radical.

Inventors: KOBORI, TAKEO, KOJIMA, ETSUKO, KONDO, KIYOSI, MURAKAMI, YASUO, SAKUMA, OSAMU, TOSHIOKA, TADASHI, TUNEMOTO, DAIEI
Applicants: SAGAMI CHEMICAL RESEARCH CENTER
Application year: 1982
Main classification: C07D501
IPC codes: C07C57, C07D277, C07D501, C07D499