GB1604739A - 7-methoxy-7-(1,3-dithietane-2-carboxamide) cephalosporanic acid derivatives - Google Patents

Description

(54) 7a-METHOXY-7fi-(1,3-DITHIETANE-2- CARBOXAMIDO)CEPHALOSPORANIC ACID DERIVATIVES (71) We, YAMANOUCHI PHARMACEUTICAL COMPANY LIMITED, a Company organised and existing under the laws of Japan of No. 5-1 Nihonbashi-Honcho 2-chome, Chuo-ku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to cephalosporin compounds having antibacterial activity.

Over the past several decades various antibiotics have been investigated and used for the treatment of various infectious diseases of animals including man but since resistant bacteria appear in many cases, there are infectious diseases which are not adequately treated by known antibiotics.

New antibiotics are constantly being sought to supplement and expand the physician's armoury, particularly for the treatment of infections involving pathogens which have become resistant to the chemotherapeutic agents now in use.

Various cephalosporins are known and a number of disclosures such as German Offenlegungsshrift Nr. 2,356,388 disclose a variety of cephalosporins or heterocyclic acyl groups very broadly.

According to this invention, there are provided cephalosporins represented by general formula I:

wherein R' represents a carboxyl group or a functional derivative residue thereof; R2 represents a hydrogen atom, a lower (C, to C4) alkyl group, a lower (C1 to C4; alkoxy group, a lower (C2 to C5) alkanoyl group, R4S(O)n wherein R4 represents a Ct to C4 alkyl group and n represents 0, 1, or 2, an aryl group, an aroyl group, a carboxyl group, a functional derivative of a carboxyl group, a lower (C2 to C5) alkenyl group, a sulfamoyl group, or a heterocyclic residue; and R3 representes a lower (Ct to C4) alkyl-substituted tetrazolyl group or a lower (Ct to C4) alkylsubstituted thiadiazolyl group, and the pharmaceutically acceptable salts thereof.

The cephalosporin compounds of this invention can have useful antibacterial activity, particularly against gram negative bacteria.

The invention also provides various processes for preparing the aforesaid cephalosporin compounds of general formula I.

The term "functional derivative residue of a carboxyl group" when represented by R' or R2 of general formula I means, for example, a carboxylic acid lower alkyl ester residue, a carboxylic acid aralkyl ester residue, a carbamoyl group, a carbazoyl group (NH2NHCO), or a cyano group. The term "lower alkyl" herein means a straight chain or branched alkyl group having 1--4 carbon atoms, such as methyl, ethyl, isopropyl, n - butyl, tert - butyl.

Examples of the aryl group are phenyl, naphthyl. Examples of the aroyl group are benzoyl, naphthoyl.

R3 of general formula I represents, as described above, a lower alkylsubstituted tetrazolyl group or a lower alkyl-substituted thiadiazolyl group; examples of the tetrazolyl group are a lH - tetrazol - 5 - yl group, and a 2H tetrazol - 5 - yl group, and examples of the thiadiazolyl group are a 1,3,4 - thiadiazolyl group, a 1,2,5 - thiadiazolyl group, and a 1,2,4 - thiadiazolyl group.

Furthermore, the groups and residues represented by Rr, R2, R3 and R4 of general formula I can have substituents. Examples of the substituted groups or residues are an N - monoalkylcarbamoyl group, an N - dialkylcarbamoyl group, and an alkoxycarbonylamino group for R; and a hydroxyalkyl group, a carboxyalkyl group, an alkoxyalkyl group, an arylalkyl group, a hydroxyphenyl group, and an alkoxyphenyl group for R2.

The compounds of this invention are 7 - methoxycephalosporin derivatives as shown by general formula I and an important feature in one preparation according to the invention is that the acyl group at the 7p - position stems from 4-substituted methylene - 1,3 - dithietane - 2 - carboxylic acid. Acylation by a 4-membered ring carboxylic acid has not hitherto been known in the field of cephalosporin chemistry and the 1,3 - dithietanecarboxylic acid itself used in one of the processes for preparing ounds of this invention shown below is a novel compound which has not been disclosed in the literature.

Compounds according to this invention can be prepared by the following processes: Process 1: In this process, a compound of general formula I is prepared by reacting 4substituted methylene - 1,3 - dithietanecarboxylic acid represented by general formula II

wherein R' and R2 have the same significance as in general formula I and 78 amino - 7a - methoxy - 3 - heterocyclic thiomethyl - A3 - cephem - 4carboxylic acid represented by general formula III

wherein R3 has the same significance as in general formula I.

In the reaction of the compound of general formula II and the compound of general formula III, the compounds may be caused to react directly with each other in the presence of a condensing agent such as N,N' dicyclohexylcarbodiimide, but it is suitable to use the compound of formula II after introducing known protective groups to R1 and R2 according to the properties of R1 and R2, and also the compound of formula III after introducing a known protective group to the carboxyl group at the 4-position. For example, when R1 and/or R2 of the compound of formula II is a carboxyl group, the carboxyl group of the compound and also the carboxyl group at the 4-position of the compound of formula III can be protected beforehand by a triphenylmethyl group, a tert-butyl group, or a benzhydryl group. Further the carboxylic acid at the 2-position of the compound of formula II or the amino group at the 7-position of the compound of formula III can be converted into a reactive derivative prior to performing the reaction. Preferred examples of the reactive derivative of the carboxylic acid are an acid halide, a mixed acid anhydride, an active ester, an active amide, an acid anhydride, and an acid azide.

The compounds of general formula II can be obtained by reacting 2,2'substituted ethylene - 1,1 - dithiol represented by the general formula IV

wherein R1 and R2 have the same significance as in general formula I and dihalogenoacetic acid or a lower alkyl ester thereof represented by general formula V

wherein X represents a halogen atom and R7 represents a hydrogen atom or a lower alkyl group and then, when the compound of formula V is the lower alkyl ester, releasing the alkyl or converting it to a reactive derivative.

The reaction of the compound of formula II and the compound of formula III or the reactive derivative thereof is usually carried out in an inert solvent under heating or cooling but in order to avoid the epimerization of the methoxy group at the 7a-position during the reaction, it is preferred to perform the reaction at low temperature, particularly at temperatures below -200C.

The compound thus formed can be converted into the compound of formula I by removing the protective group or groups in an ordinary manner.

Process 2: In this process, a compound of general formula I is prepared by reacting 3 acetoxymethyl- or 3- carbamoyloxymethyl- 7P - (4 - substituted - 1,3dithietanecarboxamido) - 7a - methoxy - A3 - cephem - 4 - carboxylic acid represented by general formula VI

wherein R1 and R2 have the same significance as in general formula I and R6 represents an acetyl group or a carbamoyl group and a heterocyclic thiol represented by general formula VII R3-SH VII wherein R3 has the same significance as in general formula I or the alkali metal salt thereof at the hydrogen atom of the mercapto group.

The reaction is performed at room temperature or under heating usually in an inert solvent. Examples of the inert solvent are acetone, dimethylformamide, methanol, ethanol, water, and a phosaphate buffer and, if necessary, they are used in admixture. When the compound of general formula VII is used in the free state, it is preferred to perform the reaction in the presence of a base such as an alkali metal hydroxide, an alkali metal carbonate, an alkali metal hydrogen carbonate, trialkylamine, pyridine, or dimethylaniline. After the reaction is over, the compound of formula I formed is isolated by acidifying the reaction mixture and recovering the precipitates thus formed or by subjecting the reaction mixture to solvent extraction. In addition, the compound of formula VI used in the process can be obtained by reacting a compound of general formula II used in Process I and 7A - amino - 7a - methoxycephalosporanic acid (R6 is an acetyl group) or 7,6 amino - 3 - carbamoyloxymethyl - 7a - methoxy - A3 - cephem - 4 - carboxylic acid (R6 is -CONH2) represented by general formula VIII

under similar reaction conditions to Process 1.

Process 3: A compound of this invention shown by general formula I is also obtained by treating a 7a - methoxy - 3 - heterocyclic thiomethylcephalosporin derivative represented by general formula IX

wherein R2 and R3 have the same significance as in general formula I and R8 represents a hydrogen atom or a substituted or unsubstituted alkyl group, under basic conditions.

In addition, when R8 of general formula IX is hydrogen, the derivative of the formula includes the tautomer of the following formula

wherein R2 and R3 are the same as above.

Appropriate bases used in this process are weak bases such as sodium hydrogencarbonate, potassium hydrogencarbonate, and sodium carbonate. The reaction is usually performed in a solvent at room temperature or under cooling.

Any solvents which do not affect the reaction may be used but preferably water or an organic solvent which is miscible with water, such as methanol, acetone, tetrahydrofuran, or dimethylformamide, is used singly or in a combination thereof.

The isolation and purification of the product from the reaction mixture are performed in conventional manner such as by extraction with organic solvent, crystallization, column chromatography.

The compounds obtained by the invention can exhibit excellent antibacterial activity, particualrly against gram negative bacteria, as shown below.

TABLE (M.l.C.) (Wml) Klebsiella Proteus Proteus Escherichia Pneumoniae Vulgaris Morgani Seratia Example No. Coli NIHJ ATCC 10031 OXK US Kono Marcescens 0.09 0.09 ' 0.78 1.56 0.78 2 0.09 0.09 0.39 0.78 0.39 3 0.78 0.39 0.78 6.25 6.25 4 0.09 0.09 0.39 0.39 0.39 5 0.19 0.39 0.78 0.78 TABLE

(M.l.C.) (y/ml) Klebsiella Proteus Proteus Escherichia Pneumoniae Vulgaris Morganii Seratia Example No. ColiNIHJ ATCC 10031 OXK US Kono Marcescens 7 0.19 0.19 1.56 0.39 0.39 8 0.78 0.39 0.78 10 0.19 0.19 1.56 1.56 0.78 11 0.19 0.19 1.56 3.13 0.78 12 0.39 0.39 0.78 6.25 6.25 13 0.39 0.39 0.78 0.39 12.5 14 0.78 0.78 3.13 15 0.19 0.09 0.78 0.39 1.56 18 0.78 0.39 0.78 3.13 3.13 19 1.56 1.56 1.56 6.25 6.25 20 0.39 0.39 0.78 3.13 0.78 21 0.19 0.09 0.78 0.39 0.39 22 0.78 0.39 1.56 1.56 0.78 24 0.78 0.78 1.56 6.25 1.56 25 0.09 0.20 0.78 27 s0.20 0.20 0.78 0.78 0.39 The compounds of formula I obtained in this invention can be easily converted into the pharmaceutically acceptable, non-toxic or effective salts thereof. These salts include the alkali metal salts such as sodium or potassium salt or salts (for example, using sodium or potassium 2 - ethyl hexanoate), ammonium salt or salts, and organic amine salt or salts such as those with procaine or ethanolamine which can be prepared by one skilled in the art by known methods.

Moreover, pharmaceutical compositions having an actibacterial activity comprising a pharmaceutical carrier and an active but non-taxic amount of the compound of forrrlJa I or a pharmaceutically acceptable salt thereof as well as methods of combatting bacterial infections by administering such a pharmaceutical composition to an infected non-human animal host in a non-toxic amount sufficient to combat such infections, are also the subject of this invention.

The compounds of this invention may be administered orally, rectally, or by injection such as subcutaneously, intramuscularly, or intravenously.

The injection of suitably prepared sterile solutions or suspensions containing an effective but non-toxic amount of the cephalosporin compound of this invention is the preferred route of administration.

The doses of the cephalosporin compound of this invention are usually 25- 3000 mg per day for an adult and can be variously changed according the condition of the disease, the age, weight, and the state of the patient.

The invention is illustrated in more detail by the following examples.

Example 1

(a) In 15 ml of methylene chloride were dissolved 0.340 g of 4 - [1 - (tert butoxycarbonyl)ethylidene] - 1,3 - dithietane - 2 - carboxylic acid and 0.206 g of pyridine. And while stirring the solution in an ice-water bath, 0.284 g of phosphorus penta chloride was added to the solution. The reaction was carried out for one hour at temperature below 10 C and then after cooling the reaction mixture to -50"C, a solution of 0.690 g of 7,6 - amino - 7a - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester in 10 ml of methylene chloride was added dropwise to the solution and then 1.6 ml of pyridine was added dropwise and the mixture was caused to react for one hour at temperatures of from -30"C to 400C.

After the reaction was over, 10 ml of 5 normal hydrochloric acid was added dropwise to the reaction mixture below 0 C and the product was extracted with methylene chloride. The extract was washed with a saturated aqueous sodium chloride solution, dried over anhydrous calcium chloride, and then methylene chloride was distilled off to provide 1.1 g of a residue. The residue was subjected to silica gel column chromatography and 0.490 g (yield 47%) of caramel-like 7p - (4 Il - - (tert - butoxycarbonyl)ethylidene] - 1,3 - dithietan - 2 - yllcarboxamido 7a - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem 4 - carboxylic acid benzhydryl ester was obtained using a mixture of ethyl acetate and n - hexane of 1:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (D-DMSO) a (ppm): 1.44 (9H, tert-butyl),

- ooc 1.56 (3H, CH3 3.49 (3H, -- -OCH3), 3.90 (3H, N ), CH3 5.10 (1 H)H of C6 and 5.15 (lah) 6.92 (lH, CH(C6H5)2), 9.68 (lH, ONH-).

(b) In 25 ml of anisole was dissolved 0.44 g of the product obtained in step (a) and while cooling the solution below 5 C with ice-water, 7.5 ml of trifluoroacetic acid was added dropwise to the solution. The reaction was performed for one hour at 5--10"C, anisole and excess trifluoroacetic acid were distilled off under reduced pressure, and the residue was powdered by adding thereto ether. After recovering the powder by filtration, the powder was washed well with ether to provide 0.271 g (yield 86.7%) of the light yellow powder of 7,6 - [4 - ( I - carboxyethylidene) - 1,3 dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - (I - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) 6 (pom):

OC 1.56 (3H, =), 3.41 (3H, - - -OCH3), CH3 3.93 (3H, N ), CH3 5.13 (2H, H of C6 and 9.57 (lH, ONH-).

Infrared spectrum (KBr) (cm-') 1870 (lactam).

Reference Example 1 In a 100 ml three-necked flask were placed 40 ml of dimethoxyethane and 10 ml of tetrahydrofuran both were deoxygenated by distillation. And while cooling the mixture below -700C by a dry ice acetone bath in nitrogen stream, 1 ml of n isopropylcyclohexylamine and 3.43 ml of a 15% n - butyl lithium n - hexane solution were added to the mixture. Then, after adding thereto 0.65 g of tert - butyl propionate, the reaction was carried out for about 30 minutes at temperature below -70 C with stirring. To the reaction mixture was added dropwise 0.332 ml of carbon disulfide at temperatures of from -750C to -730C over a period of about 30 minutes. The reaction was further carried out for 10 minutes at a temperature below -700C and then 3.4 ml of a 15% n - butyl lithium n - hexane solution was added dropwise to the reaction mixture at temperature below -70 C over a period of about 30 minutes. After carrying out the reaction for 15 minutes at a temperature below -70"C, sodium diiodoacetate, obtained before hand by reacting 0.24 g of 50% oily sodium hydride and 1.56 g of diiodoacetic acid in 10 ml of dimethoxyethane under ice-cooling, was added to the reaction mixture and the mixture was stirred overnight at room temperature.

The solvent was distilled off from the reaction mixture under reduced pressure and after adding cold ether to the residue and acidifying the residue with I normal hydrochloric acid, the product was extracted with ether. The ether extract was washed well with a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then ether was distilled off to provide 1.42 g of a brown oily product. The product was subjected to silica gel column chromatography and 0.5 g of oily 4 - [1 - (tert - butoxycarbonyl)ethylidene] - 1,3 - dithietane - 2 carboxylic acid was obtained using a mixture of chloroform, methanol, and formic acid of 95:5:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (D6-DMSO) S (ppm): 1.42 (9H, tert-butyl),

Infrared spectra (cm-1): 2970 (tert-butyl), 25202650 (-COOH), 16401740 (-COO-tert-butyl, OOH), 1360, 1250 and 840 (tert-butyl).

Example 2

(a) In 5 ml of tetrahydrofuran were dissolved 0.7 g of 7p - amino - 7a methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester and 0.35 g of 4 - [(tert butoxycarbonyl)(methoxy)methylene] - 1,3 - dithietane - 2 - carboxylic'acid and after adding thereto 0.3 g of N,N' - dicyclohexylcarbodiimide under ice-cooling, the mixture was stirred for two hours at room temperature. Insoluble matters were filtered off and the filtrate was concentrated under reduced pressure. The residue was subjected to column chromatography and 0.36 g of 7p - (4 - [(tert butoxycarbonyl)(methoxy)methylene] - 1,3 - dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester was obtained using a mixture of benzene and ethyl acetate of 85:15 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.50 (9H, tert-butyl),

-OOC 3.59 (3H) ) \ i- - -OCH3 of C7 and 3.64 (3H) CH3O 3.82 (3H, N ), CH3 4.38 (2H, H3 of C3), 4.77 (lH, 5.07 (1H, H of C6), 6.92 (1H, KH(C H5)2), 7.2-7.5 (IOH,CH(csHs)2).

(b) In 1.7 ml of anisole was dissolved 0.23 g of the product obtained in step (a) and while cooling the solution to a temperature of from -5 C to -10 C, 5.1 ml of trifluoroacetic acid was added gradually followed by stirring for 30 minutes at O- 8 C.

The reaction mixture was concentrated under reduced pressure, ether was added to the residue, and the faint brown powder formed was recovered by filtration. The powder was washed well with ether and dried under reduced pressure to provide 0.12 g of 7 - 14 - [(carboxy)(methoxy)methylenel - 1,3 dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.42 (3H, - - -OCH3 of C7),

-OOC 3.55 (3H, CH3O 3.85 (3H, N ), CH3 5.16 (2H, H of C6 and 9.59 (lH, -CONH-).

Reference Example 2

A mixture of 4.5 g of tert - butyl methoxyacetate and 10 ml of tetrahydrofuran was added to a lithium diisopropylamine solution (prepared by adding 18.2 ml of a 15% n - butyl lithium hexane solution to a mixture of 3 g of diisopropylamine and 20 ml of tetrahydrofuran at a temperature of from 0 C to -70 C) and then after adding thereto 0.9 ml of carbon disulfide at a temperature below -40 C, the resultant mixture was stirred for 20 minutes at the same temperature. Then, after adding to the resulting reaction mixture one half of the above initial amount of the above lithium diisopropylamine solution and one half of the above initial amount of carbon disulfide at a temperature of from -40"C to -70"C to cause reaction, a further quarter of the above initial amounts of the above lithium diisopropylamine solution and carbon disulfide were further added to the mixture to cause reaction, 9 g of sodium diiodoacetate was then added to the reaction mixture followed by gradual raising of the temperature and stirring for one hour at e50C and further for one hour at room temperature. The reaction mixture obtained was concentrated under reduced pressure and after adding 20 ml of 100/, hydrochloric acid to the residue formed, the product was extracted with 100 ml of benzene. The extract was washed with water and concentrated under reduced pressure. The residue formed was subjected to silica gel column chromatography and 5.6 g of 4 [(tert - butoxycarbonyl)(methoxy)methylenel - 1,3 - dithietane - 2 - carboxylic acid was obtained using a mixture of chloroform and ethanol of 10:2-5 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.52 (9H, (CH3)3COOC-), 3.67 (3H, CH3O-),

8.64 (lah, -COOH).

Example 3

(a) By treating 0.8 g of 7,3 - amino - 7a - methoxy - 3 - (1 - methyltetrazol 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester and 0.8 g of 4 - [(benzoyl)(tert - butoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid as in Example 2(a), 0.35 g of 7A - (4 - [(benzoyl)(tert butoxycarbonyl)methyenel - 1,3 - dithletan - 2 - yllcarboxamido - 7a methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester was obtained.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.24 (9H, tert-butyl), 3.60 (3H, -- -OCH3,

4.39 (2H, -CH2S- of C3),

6.92 (1H, -CH(C6H5)2), 7.2-7.6 (15H, H of aromatic ring), 7.77 (lH, -CONH-).

(b) By treating 0.23 g of the product obtained in step (a) as in Example 2(b), 0.13 g of 7,6 - (4 - I(benzoyl)(carboxy)methylene] - 1,3 - dithietan - 2 yllcarboxamido - 7a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) (ppm): 3.46 (3H, -- -OCH3),

4.32 (2H, CH2- of C2), 5.19 (1H, H of C,),

7.48 (5H, C6H5#)C-), 9.72 (1H, -CONH-).

Reference Example 3

In a mixture of 2.2 g of tert-butyl benzoylacetate and 20 ml of tert - butanol was dissolved 0.24 g of sodium hydride (50 /O in oil), and 0.6 ml of carbon disulfide was added to the solution at 1 200C followed by stirring for 40 minutes, and then 0.24 g of sodium hydride (50 / in oil) was added to the mixture followed by stirring for one hour. To the reaction mixture obtained was added 1.52 g of sodium dichloroacetate followed by stirring for 4 hours at room temperature. The reaction mixture was concentrated under reduced pressure and after adding 30 ml of 1 normal hydrochloric acid to the residue formed, the product was extracted with 30 ml of benzene. The extract was washed with water, dried, and concentrated under reduced pressure. By adding a mixture of benzene and n - hexane of 3:1 by volume ratio to the residue formed, 0.9 g of the yellowish crystals of 4 - [(benzoyl)(tert butoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid were obtained.

Example 4

(a) In 10 ml of anhydrous tetrahydrofuran were dissolved 0.3 g of 4 - I(tert butoxycarbonylXmethylthio)methylenel - 1,3 - dithietane - 2 - carboxylic acid, 0.2 g of N,N' - dicyclohexylcarbodiimide, and 0.5 g of 7,6 - amino - 7(z- methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester. Then the solution was stirred for one hour at rocm temperature. The solvent was distilled off under reduced pressure. The residue formed was subjected to silica gel column chromatography and 0.3 g of 7,6 14 - l(tert - butoxycarbonylXmethylthio)methylenel - 1,3 - dithietan - 2 yllcarboxamido - 7a - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester was obtained using a mixture of benzene and ethyl acetate of 9:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.52 (9H, tert-butyl), 2.22 (3H, CH3W) 3.78 (5H, - - -OCH3 and -CH2- of C2),

4.24 (2H, -CH3S- of C3),

5.08 (1H, H of C6), 6.92 (lH, -CH(C6H8)2), 7.35 (10H, -CH(Cll5)2), 7.80 (lH, -CONH-).

(b) In 1.5 ml of anisole was dissolved 0.3 g of the product obtained in step (a) and while stirring the solution at -50C, 5 ml of trifluoroacetic acid was added dropwise to the solution at a temperature of from -5"C to -30C followed by stirring for one hour at e30C. The reaction mixture was evaporated to dryness under reduced pressure and ether was added to the residue formed. The precipitates were recovered by filtration and washed well with ether and dried over phosphorus pentoxide under reduced pressure to provide 0.17 g of 7p (4[(carboxy)(methylthio)methylene] - 1,3 Example 5

(a) By treating 0.15 g of 4 - I(tert - butoxycarbonyl)(ethylthio)methylenel 1,3 - dithietane - 2 - carboxylic acid, 0.1 g of N,N' - dicyclohexylcarbodiimide, and 0.26 g of 7p - amino - 7a - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester as in Example 4(a), 0.14 g of 7-4 - [(tert - butoxycarbonylXethylthio)methylenel - 1,3 dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester was obtained.

Nuclear magnetic resonance spectra (CDCl3) (ppm) 1.22 (3H, CH3CH2S-), 1.52 (9H, tert-butyl), 2.68 (2H, CH3-CH2-), 3.58 (5H, H;- of C2 and - - OCH3), 3.82 (3H, - - -OCH3), 4.38 (2H, -CH2- of C2),

5.08 (1H, H of C6), 6.92 (1H, -CH(C6H5)2), 7.32 (10H, -CH(C6H5)2), 7.79 (111, -CONH-).

(b) By treating a mixture of 0.14 g of the product obtained in step (a), 1.5 ml of anisole, and 5 ml of trifluoroacetic acid as in Example 4(b), 0.07 g of 7,6 - 14 [(carboxy)(ethylthio)methylenel - 1,3 - dithietan - 2 - yl}carboxamido - 7α - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid was obtained.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 1.14 (3H, CH3CH2), 2.62 (2H, CH3CH2S-), 3.43(3H, --OCH3), 3.61 (2H, -CH2- of C2),

4.28 (2H, -CH3S- of C3), 5.08 (1H, H of C),

9.64 (1H, -CONH-).

Reference Example 5

By treating 3.4 g of tert - butyl ethylthioacetate as in Reference Example 4, 4.05 g of oily 4 - I(tert - butoxycarbonyl)(ethylthio)methylenel - 1,3 - dithietane 2 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.42 (3H, CH3CH2S-), 1.52 (9H, (C113)3COOC-), 2.68 (2H, CH3CH2S-),

9.52 (lH, -COOH).

Example 6

In 5 ml of methylene chloride was dissolved 400 mg of 4 [bis(methoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 180 mg of pyridine and further 290 mg of phosphorus pentachloride under ice-cooling, the mixture was stirred for 30 minutes. The solution was added to a solution prepared by dissolving 500 mg of 7ss - amino 7α - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - å3- cephem - 4 carboxylic acid benzhydryl ester in 10 ml of methylene chloride and cooling the solution to -20 C to -300C, and then the mixture was stirred for one hour at the same temperature. The reaction mixture was washed successively with 10 ml of water, 5 ml of dilute hydrochloric acid, and 5 ml of water, then dried over anhydrous magnesium sulfate, and distilled under reduced pressure. The residue was subjected to silica gel column chromatography to provide 450 mg of 7p - [4 {bis(methoxycarbonyl)methylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester using a mixture of chloroform and ethyl acetate of 6:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 3.58 (5H, CH3O- of C7 and CH3- of C2), 3.80 (6H, -COOCH3),

4.20 (2H, --CH2S- of C3),

5.07 (1H, H of C6), 6.93 (1H, -CH(C6H5)2), 7.36 (10H, H of phenyl of -CH(C6H5)2).

In a mixture of 4 ml of trifluoroacetic acid and 1 ml of anisole was dissolved 400 mg of 7ss - [4 - {bis(methoxycarbonyl)methylene} - 1,3 - dithietan - 2 yllcarboxamido - 7ez - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester, and the solution was stirred for one hour under ice-cooling. The reaction mixture was evaporated to dryness and the residue was mixed with ether. The product was recovered by filtration, washed well with ether, and dried overnight over phosphorus pentoxide under reduced pressure to provide 200 mg of 7,6 - [4 - (bis(methoxycarbonyl)methylene( - 1,3 - dithietan 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.44 (3H, CH3O- of C,), 3.70 --COOCH,),

4.29 (2H, -CH2S- of C3),

and H of C6 Reference Example 6

In 10 ml of anhydrous tetrahydrofuran was suspended 2.1 g of disodium 2,2 bis(methoxycarbonyl)ethylene - 1,1 - dithiolate.

After adding 2.2 g of sodium dibromoacetate to the suspension, the mixture was stirred for 2 hours at room temperature. The solvent was distilled off from the reaction mixture under reduced pressure and the residue was dissolved in 5 ml of water. The solution was adjusted to pH 3.5c.0 with dilute hydrochloric acid and extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. The residue was mixed with ether and filtered to provide 1.5 g of 4 [bis(methoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (De-DMSO) a (ppm):

Example 7

(a) In 5 ml of methylene chloride was dissolved 500 mg of [4 - bis(tert butoxycarbonyl)methylene - 1,3 - dithietane - 2 - yllcarboxylic acid. Then after adding 226 mg of pyridine and further 360 mg of phosphorus pentachloride to the solution under ice-cooling, the mixture was stirred for 30 minutes. The mixture was added to a solution prepared by dissolving 500 mg of 7,6 - amino - 7 - methoxy 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester in 10 ml methylene chloride and cooling to a temperature of from -200C to ester and the mixture was stirred for one hour at the same temperature.

The reaction mixture was washed successively with 10 ml of water, 5 ml of dilute hydrochloric acid, and 5 ml of water, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography using a mixture of chloroform and ethyl acetate of 6:1 by volume 1: ratio as the eluent to provide 300 mg of 7,6 - [4 {bis(tert - butoxycarbonyl)methylenel - 1,3 - dithietan - 2 - yllcarboxamido 7a - methoxy - 3 - (I - methyltetrazol - 5 -yl)thiomethyl- # - cephem - 4 carboxylic acid benzhydryl ester.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.50 (18 H, t-C4Hg), 3.60 (5H, CH3O- of C7 and -CH2- of C2),

5.10 (1H, H of C6), 6.94 (1H, -CH(C6H5)2), 7.38 (10H, H of the phenyl of -CH(C6115)2).

(b) In a mixture of 4 ml of trifluoroacetic acid and 0.5 ml of anisole was dissolved 200 mg of 7ss - [4 - {bis(tert - butoxycarbonyl)methylenel - 1,3 dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - As - cephem - 4- carboxylic acid benzhydryl ester. The solution was stirred for one hour under ice-cooling. Then, the solvents were distilled off under reduced pressure and ether was added to the residue formed to form precipitates which were recovered by filtration. By washing the precipitates with either, 100 mg of 7p - (4 - (dicarboxymethylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7cr methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.44 (3H, CH3O- of C7), 3.64 (211, -C112- of C2),

Reference Example 7

By following the same procedure as in Reference Example 6 using disodium 2,2 - bis(tert - butoxycarbonyl)ethylene - 1,1 - dithiolate, 4 - [bis(tert butoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (D8-DMSO) a (ppm): 1.46 (911, (CH3)3COOC-),

Example 8

(a) In 12 ml of tetrahydrofuran were dissolved 370 mg of 7ss - amino - 7α methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl- A3 - cephem - 4 carboxylic acid benzhydryl ester, 150 mg of N,N' - dicyclohexylcarbodiimide, and 150 mg of 4 - [(carbamoyl)(cyano)methylene] - 1,3 - dithietane - 2 - carboxylic acid followed by stirring for 2 hours at room temperature. Precipitates formed were filtered off and the solvent was distilled off from the filtrate under reduced pressure. The residue was subjected to silica gel column chromatography using a mixture of chloroform and iso - propanol of 9:1 by volume ratio as the eluent to provide 190 mg of 7,6 - [4 - ((carbamoylXcyano)methylenel - 1,3 - dithietan - 2 ylcarboxamidol - 7α - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 3.55 (3H, 2H, - - -CH3O and -CH2- of C2),

6.92 (1H, #2CH-), 7.30 (10H, (C6115)2CH-).

(b) In 10 ml of methylene chloride was dissolved 160 mg of the product obtained in above step (a). After adding thereto 0.5 ml of anisole, the mixture was cooled to20 C. Then, after adding dropwise 25 ml of trifluoroacetic acid to the mixture at a temperature of from -200C to -100C, the mixture was stirred for one hour at -100C to 00C. The solvent was distilled off under reduced pressure and after adding 15 ml of ether to the residue formed, the mixture was stirred for 20 minutes. Then, the mixture was filtered under reduced pressure and the precipitates thus obtained were washed well with ether and dried under reduced pressure to provide 80 mg of 7p - [4 - ((carbamoyl)(cyano)methylenel - 1,3 dithietan - 2 - ylcarboxamidol - 7a - - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) 6 (ppm): 3.44 (3H, CH3O-), 3.84 (211, H2- of C2),

4.32 (2H, -CH2- of C3), 5.17 (1H, H of C),

Reference Example 8

In 50 ml of dimethylsulfoxide was dissolved 4.8 g of disodium 2 - carbamoyl 2 - cyano - ethylene - 1,1 - dithiolate. After adding 6.28 g of tert - butyl dibromoacetate to the solution, the mixture was stirred for 48 hours at room temperature. The solvent was distilled off from the reaction mixture obtained under reduced pressure and the product was extracted with ethyl acetate. The extract was washed with water and then an aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography and 0.8 g of tert - butyl 4 - [(carbamoyl)(cyano)methylene] - 1,3 - dithietane - 2 carboxylate using a mixture of chloroform and ethyl acetate of 7:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (D6-DM SO) S (ppm): 1.47 (9H, (C113)3COOC-),

Reference Example 9

To 0.4 g of tert-butyl 4 - [(carbamoyl)(cyano)methylene] - 1,3 - dithietan 2 - carboxylate obtained in Reference Example 7 were added 2 ml of anisole and 8 ml of trifluoroacetic acid, and the mixture was stirred for one hour at room temperature. The solvents were distilled off under reduced pressure and the residue was mixed with 10 ml of ether followed by stirring for one hour. The precipitates thus formed were recovered by filtration, washed with ether, and dried under reduced pressure to provide 0.15 g of 4 - [(carbamoylXcyano)methylenel 1,3 - dithietane - 2 - carboxylic acid.

Example 9

(a) In 12 ml of methylene chloride was dissolved 0.43 g of 7p - amino - 7a methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester. After cooling the solution to -40"C, 0.65 g of pyridine was added thereto. Then, a solution (prepared by dissolving 0.2 g of 4 (dicyanomethylene) - 1,3 - dithietane - 2 - carboxylic acid in 8 ml of methylene chloride, adding 0.21 g of phosphorus pentachloride, and stirring the mixture for 25 minutes at room temperature) was added dropwise to the above-prepared mixture at a temperature of from -40"C to -250C and then the mixture was stirred for one hour at -300C to -200C. After the reaction was over, 60 ml of chloroform was added to the reaction mixture and the mixture was washed with 1% hydrochloric acid, water, and then a saturated aqueous sodium chloride solution. The organic layer formed was recovered and dried over anhydrous magnesium sulfate. The solvents were distilled off under reduced pressure and the residue was subjected to silica gel column chromatography to provide 0.37 g of 7,6 - [4 - (dicyanomethylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7ez - methoxy - 3 ( I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester using a mixture of chloroform and iso - propanol of 4'): 1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm):

6.90 (111, CH(C6H8)2), 7.30 (1 OH, H(CJ18)2).

(b) In 10 ml of methylene chloride was dissolved 0.37 g of the product obtained in above step (a). After adding 0.5 ml of anisole to the solution, the mixture was cooled to -20"C. Then, 2 ml of trifluoroacetic acid was added dropwise to the mixture at -200C to l0CC and the resultant mixture was stirred for 30 minutes at -100C to -5"C. The solvent was distilled off under reduced pressure and 20 ml of ether was added to the residue followed by stirring for 30 minutes. The mixture was filtered under reduced pressure and the precipitates obtained were washed well with either and dried under reduced pressure to provide 0.21 g of 7,6 - (4 (dicyanomethylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7fr - methoxy - 3 (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.44 (3H, - - -OCH,).

Reference Example 10

To 15 ml of methylene chloride was added 0.28 g of tert - butyl 4 I(carbamoyl)(cyano)methylenel - 1,3 - dithietane - 2 - carboxylate obtained in Reference Example 7. After adding thereto 0.33 g of pyridine and 0.43 g or phosphorus pentachloride the mixture was stirred for 30 minutes at room temperature. Then, 30 ml of chloroform was added to the reaction mixture and the mixture was washed with I normal sulfuric acid, a 5% aqueous sodium carbonate solution, and then a saturated aqueous sodium chloride solution. The mixture was then dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. The residue formed was subjected to silica gel column chromatography to provide 0.23 g of tert - butyl 4 - dicyanomethylene - 1,3 dithietan - 2 - carboxylate using chloroform as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.54 (9H, -COOC(CH3)3),

Reference Example 11

To 0.23 g of tert - butyl 4 - dicyanomethylene - 1,3 - dithietane - 2 carboxylate obtained in Reference Example 9 were added 2 ml of anisole and 6 ml of trifluoroacetic acid. And the mixture was stirred for 3 hours at room temperature. The solvents were distilled off under reduced pressure and 10 ml of hexane was mixed with the residue followed by stirring for 10 minutes. The solvent was removed by decantation. Then the same procedure was applied twice to the residue thus formed. The residue was then dried under reduced pressure to provide 0.18 g of 4 - dicyanomethylene - 1,3 - dithietane - 2 - carboxylic acid.

Example 10

(a) In 20 ml of methylene chloride was dissolved 0.714 g of 4 - (tert butoxycarbonylmethylene) - 1,3 - dithietane - 2 - carboxylic acid. Then 0.454 g of pyridine was added to the solution followed by cooling to a temperature below 5"C.

Thereafter, 0.630 g of phosphorus pentachloride was added to the mixture to cause reaction for one hour at a temperature below IOOC. The reaction mixture obtained was cooled to about -50 C and a solution prepared by dissolving 1.5 g of 7p amino - 7a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester in 15 ml of methylene chloride was added dropwise to the reaction mixture. Then, 3 ml of pyridine was added and reaction was performed for 1 hour at -300C to -35"C. After the reaction was over, 20 ml of 6 normal hydrochloric acid was added to the reaction mixture at a temperature below OOC. The methylene chloride layer formed was recovered and the aqueous layer was further extracted with 20 ml of methylene chloride. The extract was combined with the methylene chloride layer and the mixture was washed twice (each time with 20 ml of saturated aqueous sodium chloride solution), dried over anhydrous magnesium sulfate, and then the solvent was distilled off to provide 1.89 g of a brown caramel residue. The residue was subjected to silica gel column chromatography to provide 0.308 g of 7p - [(4 - tert butoxycarbonylmethylene) 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester using a mixture of ethyl acetate and n - hexane of 2:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 1.40 (9H tert-butyl), 3.44 (3H, - - -OCH3),

6.88 (lah, -CH(C8H)2), 9.66 (IH, --CONH--).

(b) In 1.7 ml of anisole was dissolved 0.3 g of the product obtained in aforesaid step (a). After cooling the solution to a temperature below -5"C, 5.1 ml of trifluoroacetic acid was added dropwise to the solution at a temperature below OOC. Thereafter, reaction was performed for 30 minutes at 50C and then for 30 minutes at 5--100C. After the reaction was over, anisole and trifluoroacetic acid were distilled off under reduced pressure and the residue was powdered with the addition of ether. The powder was washed well with ether, and dried to provide 0.1584 g of faint-yellow powdery 7,6 - [4 - (carboxymethylene) - 1,3 - dithietan 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl A3 - cephem - 4 - carboxylic aci Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.43 (3H, -OCH3),

Reference Example 12 A mixture of 80 ml of dimethoxyethane and 20 ml of tetrahydrofuran (both deoxygenated by distillation) was cooled below -700C in a nitrogen stream and after adding thereto 2 ml of N - isopropylcyclohexylamine and 6.86 ml of a 15% n butyl lithium n - hexane solution, 1.16 g of tert - butyl acetate was added dropwise to the mixture. Then, reaction was performed for 30 minutes at a temperature below -70 C and then 0.644 ml of carbon disulfide was added to the reaction mixture over a period of about 30 minutes at a temperature below 72C C. The reaction mixture colored light yellow. After further reaction for 20 minutes at a temperature below 70CC, 6.8 ml of 15% n - butyl lithium n - hexane solution was added dropwise to the reaction mixture over a period of 15 minutes at a temperature below -72 C. Thereafter, the reaction was further performed for 20 minutes at a temperature below -700C and then a solutuon containing crystals of sodium diiodoacetate prepared from 0.48 g of 50 /O sodium hydride and 3.12 g of diiodoacetic acid in 15 ml of dimethoxyethane was added to the reaction mixture.

The temperature of the reaction mixture was allowed to rise to room temperature and the reaction mixture was further reacted overnight. The solvent was distilled off and the black-brown oily material obtained was extracted with the additions of 50 ml of cold ether and 20 ml of 1 normal hydrochloric acid.

The aqueous layer was further extracted with the addition of 30 ml of cold ether and the extracts were combined. The mixture was washed twice, each time with 30 ml of saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then ether was distilled off to provide 3 g of a brown oily product The product was subjected to silica gel column chromatography to provide 0.564 g of 4 - (tert - butoxycarbonylmethylene) - 1,3 - dithietane - 2 - carboxylic acid using a mixture of chloroform, methanol, and formic acid of 95:5:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (D6-DM SO) a (ppm): 1.45 (9H, tert-butyl),

Example 11

(a) In 8 ml of methylene chloride was dissolved 0.32 g of 7p - amino - 7a methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester. After cooling the solution to -30 C, 0.48 g of pyridine was added to the solution. Then a solution (prepared by dissolving 0.37 g of 4 - [(tert - butoxycarbonyl)(methylsulfonyl)methylene - 1,3 - dithietane - 2 carboxylic acid in 8 ml of methylene chloride and adding thereto 0.25 g of phosphorus pentachloride and 0.18 g of pyridine) was added dropwise to the solution at a temperature of -400C to -30DC. After stirring the mixture for one hour at -300C to --200C, 50 ml of chloroform was added to the mixture and the resultant mixture was washed with 1% hydrochloric acid, water, and then a saturated aqueous sodium chloride solution, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was subjected to silica gel column chromatography to provide 0.25 g of 7p - 14 - [(tert butoxycarbonyl)(methylsulfonyl)methylene] - 1,3 - dithietan - 2 ylicarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - S - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester using a mixture of chloroform and isopropanol of 40:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.54 (9H, tert-butyl),

6.91 (lH, -Cll(C6118)2), 7.30 (1011, H(C8H5)2).

(b) To 2.5 ml of anisole was added 0.2 g of the product obtained in step (a). The solution was cooled to 200 C, and then 10 ml of trifluoroacetic acid was added dropwise to the mixture at -200C to -10"C. Then, after stirring the mixture for 20 minutes at the same temperature, the mixture was further stirred for 40 minutes at 10 C. The solvent was distilled off under reduced pressure, the residue formed was mixed with 30 ml of ether, and the mixture was stirred for 20 minutes. The reaction mixture was filtered under reduced pressure and the precipitates thus obtained were washed well with ether and dried under reduced pressure to provide 0.08 g of 7A - 14 - [(carboxy)(methylsulfonyl)methylene] - 1,3 - dithietan - 2 ylicarboxamido - 7xx - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (dam):

Reference Example 13

In 65 ml of tert - butanol was dissolved 2.05 g of tert - butyl methylsulfonylacetate. After adding thereto 1.32 g of potassium tert - butylate, the mixture was stirred for 5 minutes. After adding dropwise 0.91 g of carbon disulfide to the mixture and stirring for 5 minutes, 1.32 g of potassium tert - butylate was added to the mixture followed by stirring for one hour. Then, 3.8 g of diiodoacetic acid and 1.32 g of potassium tert - butylate were added to the mixture and the resultant mixture was stirred overnight. The solvent was distilled off from the reaction mixture obtained under reduced pressure. The residue formed was mixed with water, adjusted to pH 2 with 10% hydrochloric acid, and extracted with ethyl acetate. The extract was washed with water and then a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to provide 1.7 g of 4 - [(tert butoxycarbonylXmethyIsulfonyl)methylenel - 1,3 - dithietane - 2 - carboxylic acid using a mixture of chloroform and methanol of 50:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.52 (9H, (C113)3COOC-), 3.20 (3H, CH3SO2-).

The reaction mixture was mixed with 60 ml of chloroform, washed with about 30 ml of water, about 30 ml of 1-2% hydrochloric acid, and then 30 ml of water, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to provide 0.4 g of 7ss-[4 - (4 - tert butoxy - a - tert butoxycarbonylbenzylidene) - 1,3 - dithietan - 2-yl]carboxamido - 7cr methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - # - cephem - 4 carboxylic acid benzhydryl ester using a mixture of benzene and ethyl acetate of 11:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.35 (9 tert-butyl, 1.47 (9H) 3.60 (511,-- -OCH3 and -C113- of C3),

(b) In a mixture of 10 ml of trifluoroacetic acid and 2 ml of anisole was dissolved 0.4 g of the product obtained in step (a) under ice-cooling. The mixture was stirred for about 30 minutes at 100C. The solvent was distilled off under reduced pressure and 40 ml of ether was added to the residue to form precipitates, which were recovered by filtration and washed with ether to provide about 0.2 g of 7ss [4 - (- - carboxy - 4- hydroxybenzylidene) - 1,3 - dithietan - 2- yl]carboxamido - 7a - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D8-DMSO) a (ppm): 3.42 (3H, --- -OCH3),

Reference Example 14

To 8.6 ml of a 15% potassium tert - butylate tert - butanol solution were added 2.5 g of tert - butyl 4 - tert - butoxyphenylacetate and 25 ml of anhydrous tetrahydrofuran with stirring at room temperature. After stirring the mixture for 2-3 minutes, 0.6 ml of carbon disulfide was added dropwise to the mixture followed by stirring for 10 minutes. Then, 8.6 ml of a 15% potassium tert - butylate terl butanol solution was added to the mixture followed by stirring for 5 minutes; further 8.6 ml of a 15% potassium tert - butylate tert - butanol solution was added to the mixture and then 1.22 g. of dichloroacetic acid was added dropwise to the mixture at about 30 C. followed by stirring for 40 minutes at room temperature.

Then, after adding dichloroacetic acid to the reaction mixture until the mixture became weakly alkaline, the solvent was distilled off under reduced pressure and the residue was mixed with ice-water followed by washing with either.

Then, 0.5 ml of 3 normal hydrochloric acid was added to the mixture and the product was extracted with ether. To the extract was further added 0.5 ml of 3 normal hydrochloric acid. The product was extracted with ether, and the procedure was further repeated. Each extract fraction obtained was detected by silica gel thin layer chromatography, the fractions containing the product were collected and dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure to provide 1.3 g of 4 - (4 - tert - butoxy - a tert - butoxycarbonylbenzilidene) - 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (D8-DMSO)

j.3S (911) CHC 1.48(911) 3)3

Example 13

(a) In 15 ml of methylene chloride was dissolved 0.5 g of 4 - (cr - tert butoxycarbonylbenzylidene) - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 0.2 ml of pyndine and further 0.285 g of phosphorus pentachloride under icecooling, the mixture was stirred for about 20 minutes. Then, by treating the reaction mixture as in Example 12 (a) using, however, a mixture of benzene and ethyl acetate of 9:2 by volume ratio as the eluent for the silica gel column chromatography, about 0.4 g.

of 7ss - [4 - (a - tert - butoxycarbonylbenzylidene) - 1,3 - dithientane - 2 yllcarboxamido - 7α - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester was obtained.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.46 (9H tert-butyl), 3.58 (511,-- -OCH3 and -CH3- of C2),

5.08 (1H, II of C8), 6.93 (1H, H(C6H5)2), about 7.34 (ISH, C8H5- and (C8H5)2C11-).

(b) By treating 0.4 g of the product obtained in above step (a) as in Example 12(b), about 0.2 g of 7,6 - [4 - (a - carboxybenzylidene) - 1,3 - dithietane - 2 yl]carboxamido - 73 - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl A3 - cephem - 4 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (D6-DMSO) 6 (ppm): 3.41 (3H, - - -OCH3),

7.28 (soh, C1l5-).

Reference Example 15

To 15.6 g of a 15% potassium tert - butylate tert - butanol solution were added 4 g of tert - butyl phenylacetate and then 1.6 g of carbon disulfide with stirring at room temperature. After stirring the mixture for 15 minutes, 20 ml of anhydrous tetrahydrofuran and then 31.2 g of a 15% potassium tert - butylate tert - butanol solution were added to the mixture and then 2.7 g of dichloroacetic acid was added dropwise to the mixture at 30400C followed by stirring for 30 minutes at the same temperature to finish the reaction.

Then, after adding dichloroacetic acid to the reaction mixture until the mixture became weak alkaline, the solvent was distilled off under reduced pressure and the residue was mixed with ice-water followed by washing with ether. Then, 0.5 ml of 3 normal hydrochloric acid was added to the mixture and the product was extracted with ether. To the extract was further added 0.5 ml of 3 normal hydrochloric acid. The product was extracted with ether, and the procedure was further repeated. Each extract fraction obtained was detected by silica gel thin layer chromatography, the fractions containing the objective material were collected and dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure to provide about 1 g of 4 - (a - tert butoxycarbonylbenzylidene) - 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 1.40 (9H, (C113)3COOC-),

about

Example 14

(a) In 15 ml of methylene chloride was dissolved 500 mg of 4 - (tert butoxycarbonyl - N,N - dimethylcarbamoylmethylene) - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 0.19 ml of pyridine and further 163 mg of phosphorus pentachloride under ice-cooling, the mixture was stirred for about 5 minutes. The solution was added to a solution prepared by dissolving 500 mg of 7p - amino - 7ex - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid in 15 ml of methylene chloride and then adding 0.3 ml of pyridine to the solution while cooling the solution to --300C, and the mixture was stirred for about 30 minutes at the same temperature.

To the reaction mixture was added about 60 ml of chloroform. The mixture was washed with about 30 ml of water, about 30 ml of 1--2% hydrochloric acid, and then three times (each time with about 30 ml of water), and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the residue formed was subjected to silica gel column chromatography to provide 200 mg of 7p - [(4 - tert - butoxycarbonyl - N,N - dimethylcarbamoylmethylene) 1,3 - dithietane - 2 - ylcarboxamidol - 7cr - methoxy - 3 - (I - methyltetrazol 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester using a mixture of benzene and ethyl acetate of 3:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) b (ppm): 1.48 (9H, tert-C4H9-), 2.96 (6Hm, (C113)2NCO-), 3.60 (5H, CH3O and -CH2- of C2),

5.06 (1H, H of C6), 6.90 (1H, -CH(C6H5)2).

(b) In a mixture of 10 ml of trifluoroacetic acid and 2 ml of anisole was dissolved the product obtained in above step (a) under ice-cooling. And the mixture was stirred for about 30 minutes at 15"C. The solvent was distilled off under reduced pressure, 30 ml of ether was added to the residue, and the precipitates formed were recovered by filtration and washed with ether to provide 100 mg of 7p - 1(4 - carboxy - N,N - dimethylcarbamoylmethylene)- 1,3 dithietane - 2 - yl - carboxamidol - 7zx - methoxy - 3 - (1 - methyltetrazole - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 2.87 (6H, (CH3)2NCO-), 3.43 (3H, CH3O-),

Reference Example 16

By treating tert - butyl dimethylcarbamoylacclatc as in Rcfercnce Example 15, 4 - (tert - butoxycarbonyl)(dimethylcarhamoyl)mcthylenel - 1,3 ditbietane - 2 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (CDCl3) b (ppm): 1.50 (9H, (CH2)3COOC-),

Example 15

(a) In 15 ml of methylene chloride was dissolved 0.87 g of 4 - [(acetyl)(tert butoxycarbonyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 0.474 g of pyridine and further 0.624 g of phosphorus pentachloride under ice-cooling, the mixture was stirred for 30 minutes. The solution was added to a solution prepared by dissolving 0.6 g of 7h - amino - 7cr - methoxy - 3 - (I methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester in 20 ml of methylene chloride, cooling the solution to -30 C, and adding thereto 1 ml of pyridine, and the mixture was stirred for one hour at the same temperature. To the reaction mixture were added 10 ml of water, 1 ml of I normal hydrochloric acid, and 30 ml of chloroform. The chloroform layer formed was recovered, washed thoroughly with 1% hydrochloric acid to eliminate pyridine completely, then with water, dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue formed was subjected to silica gel column chromatography to provide 0.55 g of 7p - 14 - [(acetylXtert - butoxycarbonyl)methylene] - 1,3 - dithietan - 2- yllcarboxamido- 7cr methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid benzhydryl ester using a mixture of benzene and ethyl acetate of 10:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.53 (9H, tert-butyl), 2.45 (3H, CH3OC-), 3.56 (5H, - - -OCH3 and -CH2- of C2),

5.09 (1H, H of C5), 6.94 (11!, -CH(C6H5)2), 7.207.50 (10H, -CH(C6H5)2).

(b) In a mixture of 12 ml of trifluoroacetic acid and 3 ml of anisole was dissolved 0.55 g of the product obtained in aforesaid step (a) at -5"C. The mixture was stirred for 20 minutes at 150C. The solvent was distilled off under reduced pressure, 20 ml of ether was added to the residue, and the precipitates formed were recovered by filtration and washed with ether to provide 0.33 g of 7,6 - 14 [(acetyl)carboxy)methylene] - 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 2.38 (3H, CH3OC-), 3.43 (3H, -OCH3),

Reference Example 17

To 150 ml of tert - butanol was added 4.8 g of sodium hydride (50 /0 in oil).

Then 15.8 g of tert - butyl acetoacetate was added gradually to the mixture. Then, after adding thereto 7.6 g of carbon disulfide under ice-cooling, the mixture was stirred for 18 hours at room temperature. Thereafter, 4.8 g of sodium hydride (50, /Ó in oil) was added gradually under ice-cooling and after stirring the mixture for 2 hours at room temperature, 16.7 g of potassium dichloroacetate was added to the mixture followed by stirring for a further 2 hours. The reaction mixture obtained was concentrated under reduced pressure. The residue was mixed with 300 ml of ethyl acetate and 200 ml of ice-water, and the mixture was adjusted to pH 3 with 1 normal hydrochloric acid. The organic layer formed was washed with an aqueous sodium chloride solution, and extracted with a saturated aqueous sodium hydrogencarbonate solution.

The sodium hydrogencarbonate extract was washed with 50 ml of ethyl acetate, adjusted to pH 34 with I normal hydrochloric acid, and extracted with 200 ml of ethyl acetate. The ethyl acetate extract was washed with an aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and then concentrated. The residue was washed with 50 ml of a mixture of petroleum ether and ether of 10:1 by volume ratio and dissolved in 5 ml of ether. Then, 50 ml of petroleum ether was added gradually to the solution and the crystals thus precipitated were recovered by filtration to provide 10 g of 4 - [(acetyl)(tert butoxycarbonyl)methylenel - 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.53 (9H, (C113)3COOC-), 2.49 (3H, CH,OC--),

Example 16

(a) In 20 ml of methylene chloride was dissolved 1.1 g of 4 - I(tert - butoxycarbonyl)(5 - methylthio - 1,3,4 - thiadiazol - 2 - yl)methylenel - 1,3 dithietane - 2 - carboxylic acid. After adding thereto 0.462 g of pyridine and further 0.606 g of phosphorus pentachloride under ice-cooling, the mixture was stirred for 30 minutes. The solution was added to a solution prepared by dissolving 0.9 g of 7ss - amino - 7a - methoxy - 3 - (I - methyltetrazol - S - yl)thiomethyl A3 - cephem - 4 - carboxylic acid benzhydryl ester in 30 ml of methylene chloride, cooling the solution to -300C, and adding 0.75 ml of pyridine to the solution, and the mixture was stirred for one hour at room temperature. The reaction mixture was mixed with 10 ml of water and 40 ml of chloroform. Then, the chloroform layer formed was washed thoroughly with 1% hydrochloric acid to eliminate pyridine completely, then with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to provide 0.2 g of 7ss - (4 - [(tert butoxycarbonyl)(5 - methylthio - 1,3,4 - thiadiazol - 2 - yl)methylenel - 1,3 dithietan - 2 - yl}carboxamido - 7e - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester using a mixture of benzene and ethyl acetate of 10:2 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCI3) a (ppm): 1.58 (9H, tert-butyl), 2.72 (3H, CH,S--), 3.58 (3H, - - -OCH3),

6.90 (111, -CH(C6115)2), 7.10-7.50 (1011, -C11(CJ(6)2).

(b) In a mixture of 8 ml of trifluoroacetic acid and 2 ml of anisole was dissolved 0.2 g of the product obtained in above step (a) at -50C followed by stirring for one hour at 17-180C. The solvent was distilled off under reduced pressure, 20 ml of ether was added to the residue, and the precipitates formed were recovered by filtration and washed with ether to provide 0.05 g of 7p - 14 - [(carboxy)(5 methylthio - 1,3,4 - thiadiazol- 2 - yl)methylene] - 1,3 - dithietan - 2yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 2.75 (3H, CH3S-), 3.45 (3H, -OCH3),

Reference Example 18

In 100 ml of tert - butanol was dissolved 1.58 g of metallic potassium. After adding thereto 10 g of tert - butyl 5 - methylthio - 1,3,4 -thiadiazole - 2 - acetate, the mixture was stirred tor 20 minutes. Thereafter, 3.25 g of carbon disulfide was added dropwise to the mixture over a period of 10 minutes. After stirring the mixture for one hour, 4.55 g of potassium tert - butylate was added gradually to the mixture followed by stirring for 20 minutes and then 6.83 g of potassium dichloroacetate was added to the mixture followed by stirring for 18 hours. The reaction mixture was concentrated under reduced pressure, and the residue was mixed with 300 ml of ethyl acetate and 200 ml of ice-water. The mixture was adjusted to pH 34 with I normal hydrochloric acid, and the organic layer formed was washed with an aqueous sodium chloride solution, and then extracted with 1000 ml of a saturated aqueous sodium hydrogencarbonate solution. The sodium hydrogencarbonate extract was washed with 100 ml of ethyl acetate, adjusted to pH 34 with 5 normal hydrochloric acid, and then extracted with 200 ml of ethyl acetate. The ethyl acetate extract was washed with an aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and concentrated. The residue was subjected to silica gel column chromatography to provide 1 g of 4 - [(tert butoxycarbonyl)(5 - methylthio - 1,3,4 - thiadiazol - 2 - yl)methylene] - 1,3 dithietane - 2 - carboxylic acid using a chloroform and then a mixture of chloroform and methanol of 50:1 by volume ratio as eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.59 (9H, (C113)3COOC-), 2.79 (3H. CH,S-),

Example 17

(a) In 12 ml of anhydrous tetrahydrofuran were dissolved 0.2 g of 4 [(benzhydryloxycarbonylXsulfamoyl)methylene] - 1,3 - dithietane -2 - carboxylic acid, 0.25 g of 7,6 - amino - 7a - methoxy - 3 - (1 - methyletrazol - S yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester, and 0.1 g of N,N' - dicyclohexylcarbodiimide. Then the solution was stirred overnight at room temperature. Insoluble matters were filtered off and the solvent was distilled off from the filtrate under reduced pressure. The residue was subjected to silica gel column chromatography to provide 0.095 g of 7p - 14 [(benzhydryloxycarbonyl)(sulfamoyl)methylenel - 1,3 - dithietan - 2 yllcarboxamido - 7a methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester using a mixture of chloroform and isopropanol of 9:1 by volume ratio as the eluent.

(b) In 10 ml of methylene chloride was dissolved 0.095 g of the product obtained in step (a). After adding thereto 0.5 ml of anisole, the mixture was cooled to 200 C. Thereafter, 2 ml of trifluoroacetic acid was added dropwise to the mixture at -200C to -15"C and after stirring the mixture for 30 minutes at the same temperature, the resultant mixture was further stirred for one hour at 0--3"C. The solvent was distilled off from the reaction mixture under reduced pressure and 15 ml of ether was added to the residue followed by stirring for 30 minutes. Then, the reaction mixture was filtered under reduced pressure and the precipitates formed were washed well and dried under reduced pressure to provide 0.034 g of 7,6 - (4 [(carboxy)(sulfamoyl)methylenel - 1,3 - dlthietan - 2- yllcarboxamido- 7a- methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 3.42 (3H, - - -OCH3),

9.66 (111, --NHCOO-).

Reference Example 19

To 1.12 g of benzhydryl sulfamoylacetate were added 30 ml of anhydrous tetrahydrofuran and 20 ml of tert - butanol.

After cooling the mixture to -20"C, 0.177 g of sodium hydride (50 /O in oil) was added to the mixture followed by stirring for 15 minutes. To the mixture was added 0.3 g of carbon disulfide. The mixture was stirred for 30 minutes at -lO0C to -'50C.

Then, to the mixture were added 0.354 g of sodium hydride (50% in oil) and 1.05 g of diiodoacetic acid. After stirring the mixture for 20 minutes at -10 C to OOC, the mixture was stirred overnight at room temperature. The solvent was distilled off from the reaction mixture under reduced pressure and after adjusting the residue to pH 2 by adding thereto ice-water and 5% hydrochloric acid, the reaction mixture was extracted with ethyl acetate. The extract was washed twice, each time with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then the solvent was distilled under reduced pressure. The residue was subjected to silica gel column chromatography to provide 0.2 g of 4 [(benzhydryloxycarbonyl)(sulfamoyl)methylene] - 1,3 - dithietane - 2 - carboxytic acid using a mixture of chloroform and methanol of 10:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm):

6.96 (1H, (C,H,),CH--), 7.33 (ion, (C5H5)2C11-).

Example 18

(a) In 40 ml of methylene chloride was dissolved 800 mg of 4 - [(tert butoxycarbonyl)(3 - pyridyl)methylene] - 1,3 - dithietane - 2 - carboxylic acid.

After adding thereto 0.3 ml of pyridine and further 440 mg of phosphorus pentachloride under ice-cooling, the mixture was stirred for about 15 minutes. The solution was added to a solution prepared by dissolving 0.8 g of 7A - amino - 7a methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid in 25 ml of methylene chloride and adding thereto 0.7 ml of pyridine at -30"C, and the resultant mixture was stirred for 20 minutes at the same temperature. Then, 200 ml of chloroform was added to the reaction mixture and the mixture was washed twice (each time with 150 ml of aqueous 1.3% acetic acid solution) and then twice (each time with 100 ml of water), and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the residue formed was subjected to silica gel column chromatography to provide about 400 mg of 7,6 - 14 - [(tert - butoxycarbonyl)(3 - pyridyl)methylenel - 1,3 - dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid using a mixture of benzene and ethyl acetate of 2:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.47 (9H, t-C4Hg-

(b) In a mixture of 15 ml of trifluoroacetic acid and 3 ml of anisole was dissolved 400 mg of the compound obtained in above step (a) under ice cooling following by stirring for 40 minutes at 1 > 15 C. The solvent was distilled off under reduced pressure and about 50 ml of ether was added to the residue to form precipitates, which were recovered by filtration, and washed with ether. The precipitates were subjected to silica gel column chromatography to provide about 100 mg of 7,6 - I[4 - (carboxyX3 - pyridyl)methylene] - 1,3 - dithietan - 2 - ylicarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid using a mixture of chloroform, methanol, and formic acid of 50:7:1 by volume ratio as the eluent.

Nuclar magnetic resonance spectra (D6-DMSO) a (ppm):

Reference Example 20

Dy treating tert - butyl 3 - pyridylacetate as in Reference Example 15, 4 llert - butoxycarbonyl)(3 - pyridyl)methylenel - 1,3 - dithietane - 2 - carboxylic acid was obtained.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm):

Example 19

(a) In 55 ml of anhydrous tetrahydrofuran were dissolved 0.22 g of 4 [(acetyl)(carbamoyl)methylenel - 1,3 - dithietane - 2 - carboxylic acid, 0.496 g of 7p - amino - 7cr - methoxy - 3 - (1 - methyltetrazol - S - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester, and 0.194 g of N,N' dicyclohexylcarbodiimide. The solution was stirred for 2 hours at room temperature. Insoluble matters were filtered off and the filtrate was concentrated under reduced pressure. The residue formed was subjected to silica gel column chromatography to provide 0.35 g of 7p - (4 - [(acetyl)(carbamoyl)methylene] 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester using first a mixture of chloroform and ethyl acetate of 1:1 by volume ratio and then a mixture of chloroform and ethyl acetate of 1:3 by volume ratio as eluent.

(b) In a mixture of 8 ml of trifluoroacetic acid and 2 ml of anisole was dissolved 0.35 g of the product obtained in the above step (a) at -200C followed by stirring for 30 minutes at 0 C. The reaction mixture obtained was concentrated and the residue was mixed with ether followed by stirring for 30 minutes. Then, the precipita of carbon disulfide in 5 ml of anhydrous tetrahydrofuran was added dropwise to the solution under ice-cooling. To the reaction mixture obtained was added 100 ml ot anhydrous tetrahydrofuran followed by stirring for 1.5 hours at room tempeature.

Then a suspension prepared by reacting 8 g of diiodoacetic acid and 1.23 g of sodium hydride (50 /O in oil) in 100 ml of anhydrous tetrahydrofuran under icecooling was added to the mixture followed by stirring for 2.5 hours at room temperature.

The reaction mixture obtained was concentrated and the residue was mixed with 50 ml of I normal hydrochloric acid and extracted with 100 ml of ethyl acetate.

The extract was washed with 50 ml of an aqueous sodium chloride solution and the organic layer formed was extracted with 100 ml of a saturated aqueous sodium hydrogen carbonate solution. The extract was adjusted to pH 2-3 with concentrated hydrochloric acid and then extracted with 100 ml of ethyl acetate.

The extract was washed with 50 ml of an aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated.

The residue formed was dissolved in 30 ml of methylene chloride and after adding thereto 5 g of diphenyldiazomethane under ice-cooling, the mixture was stirred for 2 hours at room temperature. The reaction mixture was concentrated and the residue formed was subjected to silica gel column chromatography to provide 0.6 g of 4 - [(acetyl)(carbamoyl)methylenel - 1,3 - dithietane - 2 carboxylic acid benzhydryl ester using first chloroform and then a mixture of chloroform and methanol of 10:2 by volume ratio as eluent.

Nuclear magnetic resonance spectra (CDCl3) S (ppm): 2.32 (3H, H3COC-),

6.97 (lH, -COOCll(C6H5)2), 7.2-7.4 (10H, OoCH(CJf5)2).

(b) In a mixture of 8 ml of trifluoroacetic acid and 2 ml of anisole was dissolved 0.6 g of the product obtained in the step (a) at -200C and the temperature of the reaction mixture was raised to 10 C over a period of 20 minutes. Then, the reaction mixture was concentrated and 10 ml of a mixture of ether and petroleum ether of 1:1 by volume ratio was added to the residue to form precipitates, which were recovered by filtration to provide 0.2 g of 4 - [(acetyl)(carbamoyl)methylenel 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 2.31 (3H, H,COC--),

Example 20

(a) In 15 ml of tetrahydrofuran was dissolved 610 mg of 4 - (I - tert butoxycarbonylpropylidene) - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 1.05 g of 7,6 - amino - 7tt - methoxy - 3 - (1 - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester and 0.5 g ol N,N' - dicyclohexylcarbodiimide, the mixture was stirred for 2 hours at room temperature to cause reaction. After the reaction was over, N,N' - dicyclohexyl urea deposited was filtered off and the solvent was distilled off from the filtrate under reduced pressure to form a caramel-like residue. The residue thus formed was dissolved in 50 ml of ethyl acetate and the solution was washed with 30 ml of I normal hydrochloric acid and then water and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to provide 450 mg of a brown caramel-like residue. The residue was subjected to silica gel column chromatography (30 g of silica gel) using first benzene, then a mixture of benzene and ethyl acetate of 95:5 by volume ratio, and then a mixture of benzene and ethyl acetate of 90:10 by volume ratio as eluent, and the fractions containing the product were collected to provide about 10 mg of 7,6 - [4 - (I - tert butoxycarboxypropylidene) - 1,3 - dithietan - 2 - yl]carboxamido - 7cr - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4carboxylic acid benzhydryl ester.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.62 (3H, CH3, t), 2.08 (9H, (C113)3C-), 2.66 (211, -CH2-, q), 4.22 (3H, -OCH3, s), 4.44 (311, NCH3, s),

7.54 (1H, -CH(C8H5)2), 7.8-8.2 (1011, -CH(C6H5)2), 8.30 ( -NH-CO-).

(b) In 1.1 ml of anisole was dissolved 200 mg of the caramel-like product obtained in the above step and the solution was cooled to about 5 C in an ice-water bath. To the solution was added dropwise 3.3 ml of trifluoroacetic acid at a temperature below 10 C and thereafter the mixture was stirred for one hour at 5100C to cause reaction. Then, anisole and excessive trifluoroacetic acid were distilled off under.reduced pressure at a temperature below room temperature and the residue was mixed with 10 ml of water and extracted with a mixture of n butanol and ethyl acetate of 1:1 by volume ratio. The organic layer was collected, washed with a saturated aqueous sodium chloride solution, dried over an hydros magnesium sulfate, and then the solvent was distilled off under reduced pressure.

The residue was triturated with 10 ml of ether to provide 54 mg of 7,6 - [4 - (1 carboxypropylidene) - 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) a (ppm): 0.96 (3H, -CH3, t), 2.00 (211, -CH2-, q), 3.41 -O-CH3, s), 3.92 (3H, N--CH,, s),

9.60 (1H, -NHCO-).

Reference Example 22

A mixture of 120 ml of dimethoxyethane and 30 ml of tetrahydroturan was cooled to -74 C in a dry ice-acetone bath and then 4.0 ml of Nisopropylcyclohexylamine and then 13.72 ml of a 15% n - butyl lithium n - hexane solution were added to the mixture, whereby the temperature rose from -730C to -620C After adding 3.17 g of tert - butyl butylate and causing reaction for 30 minutes at -740C to -750C, 0.664 ml of carbon disulfide was added dropwise to the mixture over a period of 10 minutes followed by reaction for 20 minutes at that temperature. Then, 6.86 ml of a 15% n - butyl lithium n - hexane solution was added dropwise to the reaction mixture at a temperature below -72 C over a period of 10 minutes and caused to react for 30 minutes. Then, 0.332 ml of carbon disulfide was added to the reaction mixture over a period of 10 minutes and reaction was performed for 20 minutes. 3.43 ml of a 15% n - butyl lithium n hexane solution was then added dropwise to the reaction mixture at a temperature below -72"C. over a period of 13 minutes and reaction was further performed for 20 minutes at -740C. to -730C. 0.166 ml. of carbon disulfide was then added to the reaction mixture at about -74 C over a period of 6 minutes and reaction was performed for about 25 minutes. Thereafter, sodium diiodoacetate prepared by reacting 0.84 g of 50 /O sodium hydride and 5.46 g of diiodoacetic acid in 25 ml of dimethoxyethane was added to the reaction mixture followed by reaction for 30 minutes at 0--50C and then the reaction was further continued overnight at room temperature. The solvent was distilled off under reduced pressure from the reaction mixture and the residue was extracted with the addition of 50 ml of cold ether and 40 ml of I normal hydrochloric acid. The ether layer obtained was extracted twice, each time with 20 ml of saturated aqueous sodium hydrogencarbonate solution. The aqueous extracts were combined and adjusted to pH 1 with 1 normal hydrochloric acid, extracted twice with 30 ml and 20 rlih of ether, successively. The extracts were combined and washed with water, dried over anhydrous magnesium sulfate, and then ether was distilled off to provide 1.08 g of an oily product. The oily product was subjected to silica gel column chromatography and the fractions containing the product were collected using a mixture of chloroform and methanol of 10:1 by volume ratio to provide 630 mg of the brown oily 4 - (1 - carboxypropylidene) - 1,3 - dithietane - 2 - carboxylic acid.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.24 (3H,CH3, t), 1.47 (9H, (C113)3C-, s), 2.01(211, q), q),

Example 21

(a) In 10 ml of tetrahydrofuran was dissolved 350 mg of 4 - 11,2 - bis(tert butoxycarbonyl)ethylidenel - 1,3 - dithietane - 2 - carboxylic acid. After adding thereto 0.5 g of 7P - amino - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester and 219 mg of N,N' - dicyclohexylcarbodiimide, reaction was conducted for 2 hours at room temperature. After filtering off N,N' - dicyclohexylurea thus deposited, the solvent was distilled off from the filtrate and the residue was subjected to silica gel column chromatography and the fractions containing the product were collected using first benzene and then a mixture of benzene and ethyl acetate of 9:1 by volume ratio as eluent to provide 120 mg of 7p - (4 - 11,2 - bis(tert - butoxycarbonyl)ethylidenel 1,3 -dithietan - 2 - ylXcarboxamido - 7a -methoxy - 3 - (I methyltetrazol-5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.42-1.48 (18H, (CH3)3C-), 2.58 (2H, -CH2-), 3.59 (3H, --OCH,), 3.80 (3H, N-?H3), 4.36 (2H, -CH3- of C2, q),

6.92 (111, -CH(C6H5)2), 7.2-7.6 (1011, -C11(C8H5)2).

(b) In I ml of anisole was dissolved 115 mg of the product obtained in the above step (a). After cooling the solution to a temperature below in an ice water bath, 3 ml of trifluoroacetic acid was added dropwise to the solution at a temperature below 10 C. After stirring the mixture for one hour at 5--10"C, excess trifluoroacetic acid and anisole were distilled off from the reaction mixture under reduced pressure at room temperature and the residue formed was triturated with 5 ml of ether to provide 73.7 mg of 7,6 - [4 - (1,2 - dicarboxyethyldene) - 1,3 dithietan - 2 - yllcarboxamido - 7a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) b (ppm):

3.94 (3H, N--CH,), 4.30 (211, -C112- of C2), 5.16 and 5.20 (H of HOOCCH C overlapped the DMSO peak, -OCH3 overlapped the peak of water.

Reference Example 23 (CH3)3COOC\ zSs C=C CHOOOH ( CH3) 3COOCH2C s'/ To a mixture of 80 ml of diethylene glycol dimethyl ether and 20 ml of tetrahydrofuran was added 1.54 ml of diisopropylamine, and the mixture was cooled to -740C with a dry ice-acetone bath. Then, 6.86 ml of a 15% n - butyl lithium n - hexane solution was added to the mixture followed by reaction for 10 minutes at -720C to -74"C. 2.3 g of tert - butyl succinate was then added to the reaction mixture and the reaction was further carried out for 30 minutes at 740 C.

Then, 0.332 ml of carbon disulfide was added dropwise to the reaction mixture over a period of about 15 minutes and the reaction was continued for 15 minutes at -74"C. 3.43 ml of a 15% n - butyl lithium n - hexane solution was then added dropwise to the reaction mixture at a temperature below -71 0C over a period of 20 minutes and the reaction was carried out for 20 minutes at the same temperature.

Thereafter, 0.166 ml of carbon disulfide was added dropwise to the reaction mixture over a period of 13 minutes at a temperature below -72"C and the reaction was carried out for 17 minutes at that temperature. 1.715 ml of a 15% n - butyl lithium n - hexane solution was then added dropwise to the reaction mixture over a period of 10 minutes at a temperature below -71"C. Finally, 0.083 ml of carbon disulfide was added dropwise to the reaction mixture over a period of 10 minutes and the reaction was further carried out for 20 minutes at -720C to -740C.

A suspension of sodium diiodoacetate (prepared beforehand 432 mg of 50% sodium hydride and 2.8 g of diiodoacetic acid in 20 ml of diethylene glycol dimethyl ether) was added dropwise to the reaction mixture obtained in the aforesaid reaction, whereby the temperature in the system rose from -74"C to --640C. Then, the temperature was allowed to rise further and after carrying out the reaction for one hour at --50C. the mixture was stirred overnight at room temperature to cause further the reaction. Thereafter, the solvent was distilled off at room temperature under reduced pressure to provide a brown residue. The residue was mixed with 50 ml of ether and 20 ml of a cold 10% sulfuric acid and extracted with ether. The ether layer formed was extracted twice, each time with 50 ml of saturated sodium hydrogencarbonate solution. The aqueous layer obtained was mixed with 50 ml of 10% sulfuric acid and extracted with 50 ml and 30 ml of ether, successively. The ether extracts were combined and washed twice, each time with 30 ml of saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and ether was distilled off to provide 1.83 g of an oily product.

The oily product was subjected to silica gel column chromatography (70 g of silica gel) using first chloroform and then a mixture of chloroform and methanol of 50:1 by volume ratio as eluent, and the fractions containing the product were collected to provide 700-mg of 4 - [1,2 - bis(tert - butoxycarbonyl)l - 1,3 - dithietane - 2 carboxylic acid.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.22 (18H, 2x(CH3)3C-), 2.58 (2H, --CH,,-),

Mass spectra: m/e: 362 M+.

Example 22

(a) to a solution prepared by dissolving 500 mg of 7,6 - amino -7cr - methoxy 3 -(1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester in 35 ml of tetrahydrofuran was added 500 mg of 4 - I(tert butoxycarbonyl)(N - methylcarbamoyl)methyienel - 1,3 - dithietane - 2 carboxylic acid and about 400 mg of N,N' - dicyclohexylcarbodiimide, and the mixture was stirred for 3.5 hours at room temperature. The solvent was distilled off from the reaction mixture under reduced pressure and the residue formed was subjected to silica gel column chromatography to provide 300 mg of 7,6 - (4 [(carboxy)(N - methylcarbamoyl)methylenel - 1,3 - dithietan - 2 yllcarboxamido - 7a - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester using a mixture of chloroform and ethyl acetate of 4:1 by volume ratio as the eluent.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 1.52 (9H, t-C4H9-), 2.83 (3H, CH3NH CO-), 3.60 (5H, C113 and --CH,,- of C2),

(b) In a mixture of 10 ml of trifluoroacetic acid and 2 ml of anisole was dissolved 300 mg of the product obtained in the above step (a) under ice-cooling.

The solution was stirred for about one hour at 150C. The solvent was distilled off from the reaction mixture under reduced pressure and the residue was mixed with ether followed by stirring. The precipitates thus formed were recovered by filtration and washed with ether to provide 170 mg of 7,6 {4 - [(carboxy)(N methylcarbamoyl)methylene] - 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) (ppm): 2.68 (3H, CH,NHCO--), 3.42 (3H, CH,O--),

Reference Example 24

To 3 ml of 15% potassium tert - butylate tert - butanol solution were added 540 mg of tert - butyl N- methylmalonamate and 12 ml of anhydrous tetrahydrofuran with stirring at room temperature. After stirring the mixture for 5 minutes, 0.0935 ml of carbon disulfide was added dropwise to the mixture followed by stirring for 10 minutes. Then, 1.5 ml of 15% potassium tert - butylate tert butanol solution was added to the mixture followed by stirring for 10 minutes, 0.046 ml of carbon disulfide was added dropwise to the mixture followed by stirring for 10 minutes, and the same procedure was further repeated using 0.8 ml of 15% potassium tert-butylate tert-butanol solution and 0.023 ml of carbon disulfide.

Then, a suspension of sodium diiodoacetate which was separately prepared by dissolving 0.98 g. of diiodoacetic acid in 7 ml.of anhydrous tetrahydrofuran and adding 115 mg of 50% sodium hydride to the solution with stirring under cooling, was added to the above reaction mixture followed by stirring for 1 hour at room temperature to complete the reaction.

After the solvent was distilled off under reduced pressure, 150 ml of ether and 50 ml of 0.2 normal hydrochloric acid which was cooled at 0 C were added and the product was extracted with ether, then washed twice, each time with 50 ml of water. The ether layer was extracted with 50 ml of 2% sodium hydrogencarbonate, and the aqueous layer was neutralized to about pH 7.5 with I normal hydrochloric acid and extracted with 100 ml of ether. To the aqueous layer was further added 0.5 ml of I normal hydrochloric acid, followed by extraction with 100 ml of ether. This procedure was repeated. Each ether extract was subjected to silica gel thin layer chromatography using a mixture of acetonitrile, ethylacetate and water of 3:1:1 by volume ratio as the eluent; the fractions containing the product were collected and the solvent was distilled off under reduced pressure to provide 600 mg of oily 4 [(tert - butoxycarbonyl)(methylcarbamoyl)methylen - 1,3 - dithietane - 2 carboxylic acid.

* Nuclear magnetic resonance spectra (CDCl3) (ppm): 1.52 (9H, (C113)3C-), 2.84 (3H, CH,NH--),

Example 23

In 8 ml of an aqueous 5% sodium hydrogencarbonate solution was dissolved 200 mg of 7,6 - (4 - carboxy - 3 - hydroxyisothiazol - 5 - yl)thioacetamido - 7. - methoxycephalosporanic acid. The solution was stirred for 2 hours at room temperature. After the reaction was over, the reaction mixture obtained was adjusted to pH I with 2 normal hydrochloric acid and then extracted twice, each time with a mixture of n - butanol and ethyl acetate of 1:1 by volume ratio. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and the solvent was distilled off to provide 180 mg (90 X yield) of white powdery 7,6 - (4 - [(carbamoylXcarhoxy)methylenel 1,3 - dithietan - 2 - ylficarboxamido - 7cr - methoxy - A3 - cephalosporanic acid.

Nuclear magnetic resonance spectra (D6-DMSO) (ppm):

To 6 ml of water were added 300 mg of 7,6 - 14 (carbamoylXcarboxy)methylene - 1,3 - dithietan - 2 - yllcarboxamido - 7cz- methoxy cephalosporanic acid, 67.2 mg of 5 - mercapto - I - methyltetrazole and 146 mg of sodium hydrogencarbonate followed by stirring for 16 hours at 60 62"C. The reaction mixture was adjusted to pH I with 2 normal hydrochloric acid under ice-cooling, and the precipitates formed were recovered by filtration, and dried over phosphorus pentoxide under reduced pressure to provide 75 mg of light yellow powdery 7,6 - 14 - (carbamoylXcarboxy)methylene - 1,3 - dithietan - 2 yllcarboxamido - 7cr - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Example 24

A mixture of 300 mg of 7,6 - (4 - carboxy - 3 - hydroxyisothiazol - 5 yl)thioacetamido - 7cr - methoxycephalosporanic acid, 76.5 mg of 2 - mercapto - 5 - methyl - 1,3,4 - thiadiazole, 146 mg of sodium hydrogencarbonate and 6 ml of water was stirred for 12 hours at 58--600C. The reaction mixture was cooled, adjusted to pH I with 2 normal hydrochloric acid under ice-cooling, and the precipitates formed were recovered by filtration, and dried over phosphorus pentaoxide under reduced pressure to provide 95 mg (27.8% yield) of light yellow powdery 7p - 14 - I(carbamoyiXcarboxy)methylenel - 1,3- dithietan - 2 yllcarboxyamido - 7cr - methoxy - 3 - (5 - methyl - 1,3,4 - thiadiazol - 2yl)thiomethyl - A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D6-DMSO) 6 (ppm):

Example 25

In a mixture of 40 ml of methanol and 300 ml of a 5% aqueous sodium hydrogencarbonate solution was dissolved 6.0 g of 7,6 - '(4 - carboxy - 3 hydroxyisothiazol - 5 - yl)thioacetamido - 7a - methoxy - 3 - ( methyltetrazol - 5 - yl)thiomethyl- Q3- cephem 4- carboxylic acid. The solution was stirred for 5 hours at room temperature. The solution was washed with 300 ml of ethyl acetate, acidified with diluted hydrochloric acid, and extracted twice, each time with 200 ml of a mixture of n - butanol and ethyl acetate of 1:1 by volume ratio, and once with 100 ml of the same mixture. The organic layers were combined with each other, washed twice, each time with 50 ml of saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. To the residue was added 50 ml of ether and precipitates formed were recovered by filtration and washed with ether and dried to provide crude product. The crude product was purified by silica gel column chromatography using a mixture of chloroform, methanol, and formic acid of 100:20:1.5 by volume ratio as the eluent.

The fractions containing the product were collected and the solvent was distilled off under reduced pressure to provide 3.5 g of 7p - 14 - [(carbamoyl)(carboxy)methylene] - 1,3 - dithietan - 2 - yllcarboxamido - 7cr methoxy - 3 - (I - methyltetrazol - 5- yl)thiomethyl- A3 - cephem - 4 - carboxylic acid.

Nuclear magnetic resonance spectra (D-DMSO) a (ppm):

Example 26 A mixture of 300 mg of 7 - (4 - carboxy - 3 - hydroisothiazol - 5 yl)thioacetamido - 7e - methoxycephalosporanic acid, 67.2 mg of 5 - mercapto 1 - methyltetrazole, 146 mg of sodium hydrogencarbonate, and 6 ml of water stirred for 12 hours at 58-60 C. The reaction mixture was cooled, adjusted to pH I with 2 normal hydrochloric acid under ice-cooling, and the precipitates formed were recovered by filtration, and dried over phosphorus pentaoxide under reduced pressure to provide 7 - (4 - [(carbamoylXcarboxy)methylenel - 1,3 - dithietan 2 - ylfcarboxamido - 7cr - methoxy 3 - (I - methyltetrazol - 5 - yl)thiomethyl # - cephem - 4 - carboxylic acid.

Example 27

(a) In a mixture of 50 ml of chloroform and 10 ml of acetone was suspended 1.0 g of 7 - (4 - [(carbamoylXcarboxy)methylene] - 1,3 - dithietan - 2yllcarboxamido - a - methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

Then a solution prepared by dissolving about 700 mg of diphenyldiazomethane in 5 ml of chloroform was added dropwise to the suspension. The mixture was stirred for 30 minutes at room temperature and then the solvent was distilled off from the reaction mixture. The residue was subjected to silica gel column chromatography using a mixture of chloroform and ethyl acetate of 2:1 by volume ratio as the eluent to isolate and purify the product. Thus, the fractions containing the product were collected and the solvent was distilled off under reduced pressure to provide 0.8 g of 7 - l4 - I(benzhydryloxycarbonylNcarbamoyl)methyl 1,3 - dithietan - 2 - yllcarboxamido - 7cr - methoxy - 3 - ( I - methyltetrazol - 5 yl)thiomethyl - A3 - cephem - 4 - carboxylic acid benzhydryl ester.

Nuclear magnetic resonance spectra (CDCl3) a (ppm): 3.52 (5H, H of C3 and CH3 of C,),

6.90(1H) -CH(CnH5)2), 7.00 (1H) 7.30 (10H, -CH(C6H5)2).

(b) In 10 ml of chloroform was dissolved 1.0 g of 7,6 - (4 - [(benzhydryloxycarbonyl)(carbamoyl)methylene] - 1,3 - dithietan - 2 yllcarboxamido - 7ct - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid benzhydryl ester. While stirring the solution under ice-cooling, 0.3 ml of pyridine and 0.45 g of phosphorus pentachloride were added to the solution followed by stirring further for one hour at room temperature. The reaction mixture was then ice-cooled and 3 ml of water was added to the mixture.

The organic layer formed was separated from the aqueous layer, washed with 2 ml of water, dried over anhydrous magnesium sulfate, and then the solvent was distilled off und wherein Y represents

R' represents a hydroxy group, an amino group or an alkoxy (C1-C4) group; R2 represents a hydrogen atom, an amino group, a cyano group, a carboxy group, a carbamoyl group, a carbazoyl group, an aryl group, a hydroxyalkyl (C1-C4) group, an alkoxy (C1-C4)carbonyl amino group, or a di-alkyl (C,C4) carbamoyl group, R3 represents an alkyl (C,C4) group or a hydroxyalkyl (C1-C4) group; and R4 represents an alkyl (C,C4) group; or a pharmaceutically acceptable salt thereof.

WHAT WE CLAIM IS: 1. 7cr - methoxy - 7ss - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl - A3 - cephem - 4 - carboxylic acid represented by the general formula

wherein R' represents a carboxyl group or a functional derivative residue thereof; R represents a hydrogen atom, a C, to C4 alkyl group, a C, to C4 alkoxy group, R4S(O)n wherein 4represents a C1 to C4 alkyl group and n represents 0, 1 or Z, a C3 to C5 alkanoyl group, an aryl group, an aroyl group, a carboxyl group or a functional derivative residue thereof, a C2 to C5 alkenyl group, a sulfamoyl group, or a heterocyclic residue; and R3 represents a lower (C, to C4) alkyl-substituted tetrazolyl group or a lower (C, to C4 alkyl-substituted thiadiazolyl group; or a pharmaceuticaly acceptable salt thereof.

2. 7ss - {4- [(carbamoylXcarboxy)methylenel - 1,3 - dithietan - 2- yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

3. 7ss - 14 - (I - carboxyethylidene) - 1,3 - dithietan - 2 - yllcarboxamido 7α - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.

4. 7p - {4- [(carboxyXmethoxy)methylenel - 1,3 - dithietan - 2yllcarboxamido - 7cr - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

5. 7,6 {4 - [(carboxy)(methylthio)methylene] - 1,3 - dithietan - 2yllcarboxamido - 7α - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

6. 7P - 14 - [(carboxyXethylthio)methylenel - 1,3 - dithietan - 2yllcarboxamido - 7α - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.

7. 7p - 14 - (carboxymethylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7 methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.

8. A process for the preparation of 7α - methoxy - 7,6 - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl A3 - cephem - 4 - carboxylic acid represented by the general formula

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (27)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   wherein Y represents

   R' represents a hydroxy group, an amino group or an alkoxy (C1-C4) group; R2 represents a hydrogen atom, an amino group, a cyano group, a carboxy group, a carbamoyl group, a carbazoyl group, an aryl group, a hydroxyalkyl (C1-C4) group, an alkoxy (C1-C4)carbonyl amino group, or a di-alkyl (C,C4) carbamoyl group, R3 represents an alkyl (C,C4) group or a hydroxyalkyl (C1-C4) group; and R4 represents an alkyl (C,C4) group; or a pharmaceutically acceptable salt thereof.

   WHAT WE CLAIM IS: 1. 7cr - methoxy - 7ss - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl - A3 - cephem - 4 - carboxylic acid represented by the general formula

   wherein R' represents a carboxyl group or a functional derivative residue thereof; R represents a hydrogen atom, a C, to C4 alkyl group, a C, to C4 alkoxy group, R4S(O)n wherein 4represents a C1 to C4 alkyl group and n represents 0, 1 or Z, a C3 to C5 alkanoyl group, an aryl group, an aroyl group, a carboxyl group or a functional derivative residue thereof, a C2 to C5 alkenyl group, a sulfamoyl group, or a heterocyclic residue; and R3 represents a lower (C, to C4) alkyl-substituted tetrazolyl group or a lower (C, to C4 alkyl-substituted thiadiazolyl group; or a pharmaceuticaly acceptable salt thereof.
2. 2. 7ss - {4- [(carbamoylXcarboxy)methylenel - 1,3 - dithietan - 2- yllcarboxamido - 7cr - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.
3. 3. 7ss - 14 - (I - carboxyethylidene) - 1,3 - dithietan - 2 - yllcarboxamido 7α - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.
4. 4. 7p - {4- [(carboxyXmethoxy)methylenel - 1,3 - dithietan - 2yllcarboxamido - 7cr - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.
5. 5. 7,6 {4 - [(carboxy)(methylthio)methylene] - 1,3 - dithietan - 2yllcarboxamido - 7α - methoxy - 3 - (1 - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.
6. 6. 7P - 14 - [(carboxyXethylthio)methylenel - 1,3 - dithietan - 2yllcarboxamido - 7α - methoxy - 3 - ( I - methyltetrazol - 5 - yl)thiomethyl - A3 cephem - 4 - carboxylic acid.
7. 7. 7p - 14 - (carboxymethylene) - 1,3 - dithietan - 2 - yllcarboxamido - 7 methoxy - 3 - (I - methyltetrazol - 5 - yl)thiomethyl - A3 - cephem - 4 carboxylic acid.
8. 8. A process for the preparation of 7α - methoxy - 7,6 - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl A3 - cephem - 4 - carboxylic acid represented by the general formula

   wherein R1, R2 and R3 have the same significance as in Claim 1, which comprises reacting a 4 - substituted methylene - 1,3 - dithietan - 2 - carboxylic acid represented by the general formula

   wherein R1 and R2 have the same significance as above, or a functional derivative thereof, with a 7,6 - amino - 7a - methoxy - 3 - heterocyclic thiomethyl - A3 - cephem 4 - carboxylic acid represented by the general formula

   wherein R3 has the same significance as above.
9. 9. A process for the preparation of 7a - methoxy - 7,6 - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl A3 - cephem - 4 - carboxylic acid represented by the general formula

   wherein R', R2 and R3 have the same significance as in Claim 1, which comprises reacting a 3 - acetoxymethyl- (or 3 - carbamoyloxymethyl-) 7a - methoxy - 7,6 (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - A3 - cephem 4 - carboxylic acid represented by the general formula

   wherein R1 and R2 have the same significance as above and R6 represents an acetyl group or a carbamoyl group, with a heterocyclic thiol represented by the general formula 11R3 wherein R3 has the same significance as above.
10. 10. A process for the preparation of 7cr - methoxy - 7p - (4 - substituted methylene - 1,3 - dithietan - 2 - yl)carboxamido - 3 - heterocyclic thiomethyl A3 - cephem - 4 - carboxylic acid represented by the general formula

    wherein R2 and R3 have the same significance as in Claim 1 and R8 represents a hydrogen atom or a substituted or unsubstituted alkyl group, which comprises treating under basic conditions a 7, - methoxy - 3 - heterocyclic thiomethylcephalosporin derivative represented by the general formula

    wherein R2, R3 and R8 have the same significance as above.
11. 11. A compound according to Claim I wherein R3 is a I - alkyltetrazol - 5 - yl group, R' is a carboxyl group or a cyano group, and R2 is a hydrogen atom, an alkyl or alkoxy or alkanoyl or aryl or aroyl or cyano or sulfamoyl group or R4S(O)n where R4 is an alkyl group and n is 0, 1 or 2.
12. 12. A process according to Claim 8 wherein R1, R2 and R3 are as defined in Claim 11.
13. 13. A process according to Claim 9 wherein R', R2 and R3 are as defined in Claim 11.
14. 14. A compound according to Claim I wherein R3 is I - methyltetrazol - 5 yl, R' is a carboxyl or cyano group, and R2 is a carboxyl or substituted or unsubstituted carbamoyl group.
15. 15. A process according to Claim 8 wherein R', R2 and R3 are as defined in Claim 14.
16. 16. A process according to Claim 9 wherein R', R2 and R3 are as defined in Claim 14.
17. 17. A process according to Claim 10 wherein R2 is a carboxy or cyano group and R3 is a 1 - methyltetrazol - 5 - yl group.
18. 18. A compound according to Claim I substantially as hereinbefore described in any one of Examples 1 to 5, 9 to 13, and 15 to 17.
19. 19. A compound according to Claim 1 substantially as hereinbefore described in Example 25.
20. 20. A compound according to Claim I substantially as hereinbefore described in any one of Examples 6 to 8, 14, 18 to 24, 26 and 27.
21. 21. A pharmaceutical composition comprising a compound according to Claim I or Claim 20 in a pharmaceutically acceptable carrier.
22. 22. A pharmaceutical composition comprising a compound according to any of Claims 3 to 7, 11 and 18 in a pharmaceutically acceptable carrier.
23. 23. A pharmaceutical composition comprising a compound according to Claim 2, 14 or 19 in a pharmaceutically acceptable carrier.
24. 24. A method of combatting bacterial infections which comprises administering a pharmaceutical composition according to Claims 21 to 23 to an infected non-human animal host in a non-toxic amount sufficient to combat the infections.
25. 25. A process according to Claim 12 or 13 substantially as hereinbefore described in any one of Examples I to 5, 9 to 13 and 15 to 17.
26. 26. A process according to Claim 10 and substantially as hereinbefore described in Example 25.
27. 27. A process according to any of Claims 8 to 10 substantially as hereinbefore described in any one of Examples 6 to 8, 14, 18 to 24, 26 and 27.