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Title:
FUSED CYCLIC COMPOUNDS AND MEDICINAL USE THEREOF
Document Type and Number:
WIPO Patent Application WO/2003/000254
Kind Code:
A1
Abstract:
Fused cyclic compounds represented by the following general formula [I] or pharmaceutically acceptable salts thereof and remedies for hepatitis C containing these compounds: [I] wherein each symbol is as defined in the description. Because of having an effect against hepatitis C virus (HVC) based on an HCV polymerase inhibitory effect, these compounds are useful as remedies or preventives for hepatitis C.

Inventors:
HASHIMOTO HIROMASA (JP)
MIZUTANI KENJI (JP)
YOSHIDA ATSUHITO (JP)
Application Number:
PCT/JP2002/006405
Publication Date:
January 03, 2003
Filing Date:
June 26, 2002
Export Citation:
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Assignee:
JAPAN TOBACCO INC (JP)
HASHIMOTO HIROMASA (JP)
MIZUTANI KENJI (JP)
YOSHIDA ATSUHITO (JP)
International Classes:
A61K31/4184; A61K31/42; A61K31/427; A61K31/437; A61K31/4439; A61K31/4523; A61K31/496; A61K31/519; A61K31/52; A61K31/53; A61K31/55; A61K31/7076; A61K38/21; A61K45/06; A61P1/16; A61P31/12; A61P43/00; C07D209/12; C07D235/18; C07D235/30; C07D401/04; C07D401/10; C07D401/12; C07D401/14; C07D403/04; C07D403/12; C07D405/04; C07D405/12; C07D409/04; C07D409/12; C07D409/14; C07D413/04; C07D413/12; C07D417/04; C07D417/10; C07D417/12; C07D417/14; C07D419/12; C07D471/04; C07D495/04; C07H19/06; C07H19/10; C07H19/16; C07H19/20; (IPC1-7): A61K31/4184; A61K31/4439; A61K31/42; A61K31/4523; A61K31/496; A61K31/55; A61K31/427; A61K31/506; A61K31/437; C07D235/18; C07D235/30; C07D409/12; C07D401/12; C07D413/12; C07D401/04; C07D403/12; C07D417/12; C07D405/12; C07D471/04; A61P31/12; A61P1/16; A61P43/00
Domestic Patent References:
WO1999024060A11999-05-20
WO1997041884A11997-11-13
WO2001047883A12001-07-05
WO2002004425A22002-01-17
WO1996007646A11996-03-14
WO1997025316A11997-07-17
Foreign References:
JPH0625182A1994-02-01
EP0507650A11992-10-07
EP0010063A21980-04-16
Other References:
KATAEV V.A. ET AL.: "Preparation and immunomodulating effect of (1-thietanyl-3)benzimidazoles", KHIMIKO-FARMATSEVTICHESKII ZHURNAL, vol. 30, no. 7, 1996, pages 22 - 24, XP002957143
See also references of EP 1400241A4
Attorney, Agent or Firm:
Takashima, Hajime (Fushimimachi 4-chome Chuo-ku Osaka-shi, Osaka, JP)
Download PDF:
Claims:
CLAIMS
1. A process for preparing a compound of the formula: wherein R1 represents hydrogen or a metal salt; and R2 represents hydrogen, acetoxymethyl, (1methyllH tetrazol5yl)thiomethyl or (2,5dihydro2methyl6 hydroxy5oxoastriazin3yl)thiomethyl, which process comprises the steps of: (a) reacting a mixture of triphenylphosphine (Ph3P) and hexachloroethane (C2C16) or carbon tetrachloride (CC14) with an organic acid of the formula: in an organic .solvent to give an acyloxyphosphonium chloride derivative of the formula: (b) acylating a silylated derivative of 7ACA of the formula (V) : wherein R is the same as defined above, with t acyloxyphosphonium chloride derivative without i isolation.
2. The process of Claim 1 , wherein the organic solven is selected from the group consisting o dichloromethane, acetonitrile and tetrahydrofuran.
3. The process of Claim 1, wherein the silylate derivative is prepared by silylating 7ACA or it derivative with a silylating agent selected from th group consisting of dichlorodimethylsilane chlorotrimethylsilane, hexamethyldisilazane and N,0 bistrimethylsilylacetamide in an organic solvent i the presence or absence of a base.
4. The process of Claim 3, wherein the base is selecte from the group, consisting of triethylamine, pyridin and N,Ndimethylaniline.
5. The process of Claim 1, wherein the acylatio reaction is carried out for 1 to 3 hours at 5°C t 40°C.
6. The process of Claim 1, wherein triphenylphosphine hexachloroethane or carbon tetrachloride is used i the amounts of 1.0 to 1.3 equivalents to the organi acid of the formula (III) .
Description:
PROCESS FOR THE PREPARATION OF CEPHEM DERIVATIVES

TECHNICAL FIELD

The present invention relates to a novel process for preparing β-lactam derivatives, which are a useful antibiotic, having the formula (I) :

wherein R 1 represents hydrogen or a metal salt; and R 2 represents hydrogen, acetoxy methyl, (2, 5-dihydro-2- methyl-6-hydroxy-5-oxo-as-triazin-3-yl)thio ethyl or (1- methyl-lH-tetrazol-5-yl)thiomethyl.

BACKGROUND ART

Hitherto, a number of processes for the preparation of semi-synthesized β-lactam antibiotic materials have been proposed.

For instance, it is well known that an acylated compound of the formula (I) above can be prepared by converting an amino-protected organic acid of the formula

(II):

0

OCH-

wherein R 3 is an amino-protecting group, into its activated derivatives, and then by acylating 7-ADCA (7- aminodesacetoxycephalosporanic acid) , 7-ACA (7-aminocepha- losporanic acid) or its derivatives with the activated derivatives.

The activated derivatives of the compound of the formula (II) may include an acid chloride, an acid anhydride, an activated ester, an activated amide, an activated amide solvate, and so forth.

In order to use an acid chloride as the activated derivative, the organic acid (II) is reacted with thionyl chloride (S0C1 2 ) , phosphorous trichloride (PC1 3 ) , phosphorous pentachloride (PC1 5 ) , or phosphorous oxychloride (P0C1 3 ). The resulting acid chloride is acylated with 7-ADCA, 7-ACA or its derivatives followed by removing the protecting R 3 group to give a compound of the formula (I) : see Japanese Patent Application Kokai No. 52-102,096; 53-34,795; 53-68,796; 54-52,096; and 54- 157,596; as well as British Patent No. 2,025,933.

However, the process mentioned above must be carried out under severe and complicated reaction conditions, because the process is subject to protection and deprotection of the a ino group in the organic acid. This process further suffers from the defect that the acid chloride is unstable.

In another method, 2-pyridinethioeste , 2-benzothia- zole ester, or 1-hydroxy benzotriazole ester is synthesized from an organic acid of the formula (III) :

0

and then the resulting ester is acylated with 7-ADCA, 7- ACA or its derivatives to give a compound of the formula (I): see Japanese Patent Application Kokai No. 52- 102,293; 54-95,593; and 56-152,488.

However, this process shows relatively low yields due to a side reaction accompanied when preparing the activated esters. And the process must be carried out at a high reaction temperature for a long period of reaction time during the acylation step, and requires a step of removing the by-products resulted from the process.

It has also been reported that in order to resolve the problems encountered in utilizing the activated esters, an activated amide solvate of a compound of the formula (III) is isolated from an organic solvent, and then is acylated with 7-ACA or its derivatives to give a compound of the formula (I) : see European Patent No. 175,814. However, this process has the disadvantages that it is difficult to isolate the activated amide solvate from the organic solvent used, and that it must be carried out under the substantially similar reaction conditions to those in the cases involving an activated ester or an activated amide, requiring a high reaction temperature and a long period of reaction time.

Meanwhile, T. Fujisawa et al. have reported in Chem. Letters, 1267 (1983) that a lithium carboxylate

derivative is reacted with dichlorophosphoran to give corresponding acyloxyphosphonium salt derivative, and the the resulting acyloxyphosphonium salt is reacted with Grignard reagent to give a corresponding diketone.

DISCLOSURE OF INVENTION

Based on the Fujisawa's report, the present inventor have studied a process for preparing β-lactam derivative of the formula (I) , and discovered that a acyloxyphosphonium chloride derivative obtained from an aminothiazole derivative of the organic acid (III) makes it possible that the acylation of 7-ACA or its derivatives with organic acid can be proceeded without the isolation of the acyloxyphosphonium chloride to give the final product, β-lactam derivative, in good purity and high yield. Based on the above discovery, the inventors have now completed the present invention.

Therefore, an object of the present invention is to provide a new process for preparing β-lactam derivative of the formula (I) above, by which the disadvantages of the prior art processes have been eliminated.

Another object of the present invention is to provide a novel process for preparing more economically and simply a compound of the formula (I) above in higher yields and purity as compared with the prior art processes.

According to the present invention, a novel process for preparing cephe derivatives of the formula (I) above, which comprises steps of: reacting a mixture of triphenylphosphine and hexachloroethane or ' carbon tetrachloride with an organic acid of the formula (III) :

0

in an organic solvent to give an acyloxyphosphoniu chloride derivative of the formula (IV) :

acylating a derivative of 7-ACA of the formula (V) :

wherein R ~ is the same as defi •ned above, whi •ch has been previously silylated with a silylatmg agent in an organic solvent in the presence or absence of a base, with the acyloxyphosphonium chloride derivative without its isolation.

The process of the present invention can be represented by the following reaction scheme :

Ph 3 P + C 2 C1 6 I

[Ph 3 P 'i" Cl ]Cl "

tion

R 1 and R 2 are the same as defined above.

The acyloxyphosphonium chloride derivative can be synthesized by first reacting triphenylphosphine with hexachloroethane or carbon tetrachloride in an organic solvent to give dichlorophosphoran, which is then reacted with an aminothiazole derivative of the formula (III) .

For identifying the acyloxyphosphonium chloride synthesized, a number of attempts to isolate it, such as flash column chromatography and crystallization in a nonpolar solvent, etc. , have been made. However, since

the acyloxyphosphonium chloride compound is unstable and easily decomposable, its isolation could not be achieved. Thus, the acyloxyphosphonium chloride derivative is synthesized using CDCI 3 as a solvent, and then directly sampled followed by identification of its chemical structure by means of the -^H-NMR spectra.

Organic solvents for the above reaction may preferably include tetrahydrofuran, dichloromethane and acetonitrile, etc. , and most preferably dichloromethane.

Triphenylphosphine and hexachloroethane or carbon tetrachloride are each preferably used in amounts of 1.0- 1.3 equivalents to an organic acid of the formula (III) .

The reaction for preparing the acyloxyphosphonium chloride is carried out at 0-30°C. After 0.5-3.0 hours, the acyloxyphosphonium chloride derivative of the formula (IV) is obtained.

Organic solvents for silylation of the compound of the formula (V) may include tetrahydrofuran, dichlorome¬ thane, and acetonitrile, etc., and most preferably dichloromethane. Silylation agents may include dichloro- dimethylsilane, chlorotrimethylsilane, hexamethyldisila- zane, and N,0-bis-trimethylsilylacetamide, etc. The silylation agents are used in amounts of 2.0-4.0 equivalents to the compound of the formula (V) .

As the base, triethylamine, pyridine and N,N- dimethylaniline, etc. may be preferably used. The silylation reaction is preferably carried out at 10-45°C for 0.5-2.0 hours.

The acylation reaction to prepare β-lactam

derivatives of the formula (I) is appropriately carried out between -5 °C and 40°C for 1-3 hours. This reaction is carried out stoichiometrically. When the reaction is completed, a base such as triethylamine and sodium bicarbonate, and water are added to the reaction mixture, and two layers are then separated. Then, a mixture of organic solvents is added to the aqueous layer, and then the pH of the aqueous layer is adjusted to an isoelectric point to give the final product, β-lactam derivatives of the formula (I) , in precipitate form.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in greater detail by way of the following examples. It should be, however, noted that the examples are presented for illustration purpose only and should not be construed as limiting the invention which is properly delineated in the claims.

EXAMPLE l: 7-r X2-f2-AMINOTHIAZOL-4-YL)-2-S-CT-METHOXYIMI- NO1-ACETAMIDO1CEPHALOSPORANIC ACID

Step A: Into a 3-neck flask, 12.14 g of triphenylphos- phine, 10.96 g of hexachloroethane and 150.0 ml of dichloromethane were placed. The resulting mixture was stirred for 1 hour at about 20°C. Then, to the mixture, 8.88 g of 2-(2-aminothiazol-4-yl)-2-syn-methoxyiminoacetic acid was added. The resulting mixture was further stirred for 1.5 hours at 20°C to give a reaction mixture.

Step Br Into a 3-neck flask, 10.0 g of 7-aminocephalo- sporanic acid, 150.0 ml of dichloromethane and 12.32 g of N,0-bis-trimethylsilylacetamide were added. The resulting mixture was stirred for 1 hour at about 30°C. To the

mixture, the reaction mixture obtained from Step A was added dropwise at 20°C. The resulting mixture was stirred for 1 hour. Upon completion of the reaction, 14.0 g of sodium bicarbonate and 180.0 ml of water were added to the reaction mixture which was then stirred to separate a water layer. 90.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.6 to precipitate white crystals. The resulting crystals were filtered out and dried to give 15.02 g (90.0%) of the title compound.

^ H MR (DMS0-d 6 , β ppm) : 2.0(s,3H); 3.5(AB,2H); 3.8(s,3H); 4.7(q,2H); 4.8(d,2H); 5.8(dd,lH); 6.8(s,lH); 7.2(S,2H); 9.5(d,lH).

EXAMPLE 2; 7-T T2- (2-AMIN0THIAZ0L-4-YL)-2-Sy.V-METHOXYIMI- N01-ACETAMID01CEPHAL0SP0RANIC ACID

Step A: The same procedure as in Example 1, Step A was repeated to give a reaction mixture.

Step B: Into a 3-neck flask, 10.0 g of 7-aminocephalo- sporanic acid, 150.0 ml of dichloromethane and 9.28 g of triethylamine were placed. To the mixture, 9.97 g of chlorotrimethylsilane was added dropwise at 15°C. The resulting mixture was stirred for 1.5 hours, to which the reaction mixture obtained from Step A was then added. After stirring for 1 hour at 20°C, 16.0 g of sodium bicarbonate and 200.0 ml of water were added to the mixture which was then stirred again to separate the water layer. 100.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.6 to precipitate white crystals. The resulting crystals were filtered and

dried to give 14.55 g (87.2%) of the title compound.

EXAMPLE 3; 7-rT2-f2-AMINOTHIAZOL-4-YL)-2-SFff-METHOXYIMI- NO1-ACETAMIDO1CEPHALOSPORANIC ACID

The same procedure as in Example 1 was repeated, except that tetrahydrofuran in the same amount was used in place of dichloromethane. Then, 14.0 g of sodium bicarbonate and 180.0 ml of water were added to the resulting mixture. After the mixture was saturated with NaCl while stirring, the water layer was separated. 90.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.6 to precipitate white crystals. The resulting crystals were filtered out and dried to give 13.97 g (83.7%) of the title compound.

EXAMPLE At 7-TT2-f2-AMINOTHIAZOL-4-YL.-2--gFW-METH0XYIMI- NO )-ACETAMIDOTCEPHALOSPORANIC ACID

The same procedure as in Example 1 was repeated, except that acetonitrile in the same amount was used in place of dichloromethane. Then, the resulting mixture were treated in the same manner as described in Example 3 to give 14.10 g (84.5%) of the title compound.

EXAMPLE 5: 7-Tr2-f2-AMIN0THIAZ0L-4-YL)-2-SYJf-METHOXYIMI- NO1-ACETAMIDO1CEPHALOSPORANIC ACID

The procedure similar to that described in Example 1 was carried out using 9.77 g of hexamethyldisilazane in place of N,0-bis-trimethylsilyl acetamide. Then, the resulting mixture was treated in the same manner as described in Example 3 to give 14.49 g (86.8%) of the title compound.

EXAMPLE 6: 7-f ϊ 2- (2-AMINOTHIAZOL-4-YL)-2-SYW-METHOXYIMI- NO1-ACETAMIDO1CEPHALOSPORANIC ACID

Step A: The same procedure as in Example 1 was repeate to give a reaction mixture.

Step B: Into a 3-neck flask, 10.0 g of 7-aminocephalo sporanic acid, 150.0 ml of dichloromethane and 9.56 g o N,N-dimethyl aniline were placed. To the mixture, 9.47 of dichlorodimethylsilane was then added dropwise a 15°C. The resulting mixture was stirred for 1.5 hours. To this mixture, the reaction mixture obtained from Step was added. After stirring at 20°C for 1 hour, 17.0 g o sodium bicarbonate and 200.0 ml of water were added to th reaction mixture. The mixture was stirred again, and water layer was separated therefrom. 100.0 Ml of mixtur solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.6 to precipitate white crystals. The resulting crystals were filtered and dried to give 14.35 g (86.0%) of the title compound.

EXAMPLE 7; 7- 12- (2-AMINOTHIAZOL-4-YL)-2-SYN-METHOXYIMI- NO1-ACETAMIDO1-3- ϊ (1-METHYL-1H-TETRAZOL-5- YDTHIOMETHYL1-3-CEPHEM-4-CARBOXYLIC ACID

Step A: Into a 3-neck flask, 12.14 g of triphenylphos- phine, 10.96 g of hexachloroethane and 180.0 ml of dichloromethane were placed. The mixture was stirred for 1 hour at 20°C, to which 8.88 g of 2-(2-aminothiazol-4- yl) -2-syn-methoxyimino acetic acid was added. The resulting mixture was stirred for 1.5 hours at 20°C to give a reaction mixture.

Step B: Into a 3-neck flask, 12.05 g of 7-amino-[3-(l-

methyl-lH-tetrazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid, 180.0 ml of dichloromethane and 12.32 g of N,0-bis- tri ethylsilyl acetamide were placed. The mixture was stirred for 1 hour at 30°C. To the mixture, was added dropwise the reaction mixture obtained from Step A at 20°C. The resulting mixture was then stirred for 1.5 hours. After completion of the reaction, 13.0 g of sodium bicarbonate and 180.0 ml of water were added to the reaction mixture. After the mixture was stirred, the water layer was separated. 95.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.8 to precipitate crystals. The resulting crystals were filtered out and dried to give 16.60 g (88.4%) of the title compound.

1 HNMR (D 2 0/NaHC0 3 , £ppm) : 3.84(d,2H); 4.01(s,3H); 4.05 (s,3H) 5.18(d,lH); 5.76(d,lH); 7.00(s,lH).

EXAMPLE 8: 7-r \ ~ 2- (2-AMIN0THIAZ0L-4-YL)-2-SYff-METHOXYIMI-

N01-ACETAMIDO1-3-T (1-METHYL-1H-TETRAZOL-5- YIs)THIOMETHYL1-3-CEPHEM-4-CARBOXYLIC ACID

The same procedure as in Example 7 was repeated, except that acetonitrile in the same amount was used in place of dichloromethane. Then, 13.0 g of sodium bicarbonate and 170.0 ml of water were added to the resulting reaction mixture. After the reaction mixture was saturated with NaCl while stirring, a water layer was separated by extracting with 150 ml of dichloromethane. 80.0 Ml of a mixture solvent of ethyl acetate and n- butanol (8:2) was added to the water layer which was then adjusted to a pH of about 2.8 to precipitate crystals. The resulting crystals were filtered out and dried to give 15.90 g(84.7%) of the title compound.

EXAMPLE 9: 7- ϊ ϊ 2- (2-AMINOTHIAZOL-4-YL) -2-.SΥW-METHOXYIMI- NOl-ACETAMIDO1-3-CEPHEM-4-CARBOXYLIC ACID

Step A: Into a 3-neck flask, 12.14 g of triphenylphos phine, 10.96 g of hexachloroethane and 170.0 ml o dichloromethane were placed. The mixture was stirred for hour at about 20°C, to which 8.88 g of 2-(2-aminothiazol 4-yl) -2-syn-methoxyimino acetic acid was added. Th mixture was stirred for 1.5 hours at 20°C to give reaction mixture.

Step B: Into a 3-neck flask, 7.35 g of 7-amino-3-cephem-4 carboxylic acid, 170.0 ml of dichloromethane and 7.84 g o pyridine were placed. To the mixture, 11.84 g of dichlorodimethylsilane was added dropwise at 10°C. The resulting mixture was stirred for 1.5 hours at 20°c. To this mixture, the reaction mixture obtained from Step A was added, and then the resulting mixture was stirred for 1.5 hours at 10°C. After completion of the reaction, 16.5 g of sodium bicarbonate and 210.0 ml of water were added to the mixture. The mixture was stirred, and then a water layer was separated. 100.0 Ml of mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer, which was then adjusted to a pH of about 2.9 to precipitate crystals. The resulting crystals were filtered out and dried to give 12.61 g (89.6%) of the title compound.

' HNMR (DMSO-d 6 , øppm): 3.58(bs,2H); 3.84(s,3H); 5.12 (d,lH); 5.84(d,lH); 6.51(s,lH) ; 6.77(s,lH); 7.26

(bs,2H) ; 9.65(d,lH) .

EXAMPLE 10; 7-f 12-(2-AMINOTHIAZOL-4-YL)-2-5YJff-METH0XYIMI- NO1-OXO-AS-TRIAZIN-3-YL THIOMETHYL1-3-CEPHEM 4-CARBOXYLIC ACID

5 Step A: Into a 3-neck flask, 12.14 g of triphenylpho sphine, 10.96 g of hexachloroethane and 150.0 ml o dichloromethane were placed. The mixture was stirred fo 1 hour at about 20°C, to which 8.88 g of 2-(2- aminothiazol-4-yl)-2-syn-methoxyimino acetic acid was i 0 added. The mixture was stirred for 1.5 hours at 20°C to give a reaction mixture.

Step B: Into a 3-neck flask, 13.62 g of 7-[amino-3- (2,5-dihydro-2-methyl-6-hydroxy-5-oxo-as-triazin-3-yl)- 5 thiomethyl]-3-cephem-4-carboxylic acid, 200 ml of dichloromethane and 26.13 g of N,0-bis-trimethylsilylace- ta ide were placed. The mixture was stirred for 1 hour at about 30°C. To the resulting mixture, was added dropwise the reaction mixture obtained from Step A at lθ°C. The 0 resulting mixture was then stirred for l hour. After completion of the reaction, 16.0 g of sodium bicarbonate and 180.0 ml of water were added to the reaction mixture. After the mixture was stirred, the water layer was separated. 50.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the water layer adjusted to a pH of about 3.1 to precipitate crystals. The resulting crystals were filtered out and dried to give 18.45 g (90.6%) of the title compound.

1 HNMR (DMSO-d 6 , ppm) : 3.2(d,2H); 3.61(S,3H); 3.95

(s,3H); 4.21(d,2H); 5.18(d,lH); 5.72(d,lH); 6.95 (s,lH); 7.2(bs,2H); 9.45(d,lH).

EXAMPLE 11: 7- [ f2- (2-AMINOTHIAZOL-4-YL) -2-SYN-METKOXYim- NQ1-ACETAMIDO!-3-T ( 2.5-DIHYDRO-6-HYDROXY-2- METHYL-5-OXO-AS-TRIAZIN-3-YL)THIOMETHYL1-3- CEPHEM-4-CARBOXYLIC ACID

The same procedure as in Example 10 was repeated, except that acetonitrile in the same amount was used i place of dichloromethane. Then, the resulting reactio mixture was treated in the same manner as described i Example 3 and adjusted to a pH of about 3.1 t precipitate crystals. The resulting crystals were filtered out and dried to give 17.53 g (86.1%) of the title compound.

EXAMPLE 12; 7- [ [ 2- (2-AMINOTHIAZOL-4-YL)-2-SYy r -METHOXYIMI-

NOl-ACETAMIDO!-3-r ( 2 .5-DIHYDRO-6-HYDROXY-2- METHYL-5-OXO-AS-TRIAZIN-3-YL)THIOMETHYL1-3- CEPHEM-4-CARBOXYLIC ACID

Step A: The same procedure as in Example 10 was repeated to give a reaction mixture.

Step B: Into a 3-neck flask, 13.62 g of 7-[amino-3-(2,5- dihydro-2-methyl-6-hydroxy-5-oxo-as-triazin-3-yl)thiome- thyl]-3-cephem-4-carboxylic acid, 200.0 ml of dichloro¬ methane and 14.84 g of triethylamine were placed. To the mixture, 16.58 g of dichlorodimethylsilane was added dropwise at 15°C. The resulting mixture was stirred for 1 hour, to which the reaction mixture obtained from Step A was then added, and the resulting mixture was stirred for 1 hour at 10°C. After completion of the reaction, 17.0 g of sodium bicarbonate and 210.0 ml of water were added to the reaction mixture. After the mixture was stirred, the water layer was separated. 100.0 Ml of a mixture solvent of ethyl acetate and n-butanol (8:2) was added to the

water layer, which was then adjusted to a pH of about 3.1 to precipitate crystals. The resulting crystals were filtered out and dried to give 17.30 g (85.0%) of the title compound.

EXAMPLE 13; 7-TT2- (2-AMIN0THIAZ0L-4-YL)-2-SYff-METHOXYIMI- NO1-ACETAMIDO1CEPHALOSPORANIC ACID

The same procedure as in Example 1 was repeated, except that carbon tetrachloride in the same equivalent was used in place of hexachloroethane. Then, the resulting reaction mixture was treated in the same manner as described in Example 1 to give 14.67 g (87.9%) of the title compound.

EXAMPLE 1 ; 7-Tr2-f2-AMINOTHIAZOL-4-YL)-2-S.CT-METHOXYIMI- NOT-ACETAMID01-3-f ( 2 .5-DIHYDRO-6-HYDROXY-2- METHYL-5-OXO-AS-TRIAZIN-3-YLΪTHIOMETHYL1-3- CEPHEM-4-CARBOXYLIC ACID

The same procedure as in Example 10 was repeated, except that carbon tetrachloride in the same equivalent was used in place of hexachloroethane. Then, the resulting reaction mixture was treated in the same manner as described in Example 10 to give 17.8 g (87.4%) of the title compound.

INDUSTRIAL APPLICABILITY

As described above, the present invention is featured by removing the steps of protecting and deprotecting the amino group in the aminothiazole derivative (III) . Also, the subsequent acylation step can be carried out without isolation of the acyloxyphosphonium chloride of the formula (IV) . Furthermore, the reactions involved may be

carried out at near room temperature in a relatively shor reaction time.

In addition to the advantages mentioned above, afte the completion of the reactions involved, the separatio of the desired product can be easily achieved by adding mixture of organic solvents to the aqueous layer. Thus, according to the present invention β-lactam derivatives, which are a useful antibiotic, of the formula (I) abov and prepared more economically and simply in high yield and purity.