JPH042597B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel cephalosporin derivative, and more particularly to a cephalosporin having excellent antibacterial activity represented by the following general formula (). [In the formula, R ₁ is R ₂ represents hydrogen or methoxy group (provided that R ₁ , R ₂ represents only hydrogen), and R ₃ represents hydrogen, a salt with an organic base, or a physiologically acceptable metal ion. ] An object of the present invention is to provide a cephalosporin that has excellent antibacterial activity against a wide range of pathogenic bacteria, mainly including Gram-negative bacteria and Gram-positive bacteria. Cephalosporin compounds are widely used for the treatment and prevention of infections caused by pathogenic bacteria. In many cases, it is desirable to use cephalosporin antibiotics that are active against both Gram-positive and Gram-negative bacteria, and various types of broad-spectrum cephalosporins are being developed. The cephalosporin of the present invention has a 5-(2-
Amino-2-carboxy)ethyl-1,3,4-
It is a new cephalosporin that has an S bond in thiadiazole, and these cephalosporins are
It has high antibacterial activity against Gram-positive bacteria and Gram-negative bacteria, and also has high stability against β-lactamases produced by various Gram-negative bacteria. The amino acid at position 3 of the present invention is D, L,
Any DL form can be used. As a typical compound of the present invention, the following compound () can be mentioned, and its MIC against Gram-negative bacteria is as follows.

【table】

[Table] Comparison of compound () with cefotaxime and cefoperazone, at an inoculum amount of 10 ⁸ cells/ml,
It exhibits particularly excellent effects and has the great feature of being unaffected by the amount of inoculated bacteria. Next, compound () has extremely low toxicity, and exhibits particularly low toxicity among third generation cephalosporins. Acute toxicity studies of this compound in mice showed that upon i.p.
LD ₅₀ was 9-12 g/Kg. Furthermore, the 3-position 5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole derivative has strong antibacterial activity and low toxicity, as well as intestinal absorption as shown in the example below. This should be improved. For example, when comparing the maximum blood concentrations of cefotaxime, Compound (), and Compound () after oral administration to rats, their effects are observed.

[Table] Blood concentration was measured by HPLC method and bioassay method (E. coli was used as the test organism). Next, the compound according to the present invention can be synthesized by approximately two routes. In the synthesis method (), R ₁ -COOH is reacted with a 7-ACA derivative in the presence of a suitable binder such as dicyclohexylcarbodiimide, or R ₁ -COOH is reacted with an activated form such as an active ester, a mixed acid anhydride, etc. After converting to things etc., 7-ACA
There is a method of reacting with derivatives. Furthermore,
It is also possible to react after converting it into an acid chloride like R ₁ -COCl. In the above condensation, an organic solvent that does not participate in the reaction, such as tetrahydrofuran, dioxane, ethyl acetate, dimethylformamide, methylene chloride, acetone, etc., is selected. Furthermore, in the reaction of acid chloride, etc., it is also possible to use an aqueous system. Next, the conversion reaction of the acetoxymethyl group at the 3-position with 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole is carried out using water or a mixed solvent such as methanol, acetone, etc. In this method, sodium bicarbonate or triethylamine is used as a base to control the reaction system.
While controlling the pH around 6-7, 30-30
1 to 20 hours, preferably 2 hours at 100℃
The 3-position conversion reaction can be carried out by reacting for ~10 hours. During this time, the reaction system is preferably under a nitrogen atmosphere. Next, regarding the route (), to give an example, the amino group of 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole is protected, for example, t- After butyloxycarbonylation, the acetoxymethyl group at the 3-position of 7-ACA (or its derivatives) is treated in a mixed solvent system of water and acetone using sodium hydrogen carbonate as a base while controlling the pH to 6 to 7. React at 30-100°C for 1-20 hours. The 4-position carboxyl group of the obtained compound 7-ACA derivative, the 5-(2-amino-2-
The carboxyl group of carboxy)ethyl-1,3,4-thiadiazole can be trimethylsilylated or left free and condensed with RCOOH or its carboxylic acid active form (e.g., active ester, mixed acid anhydride, acid chloride). urge After that, decomposition with trifluoroacetic acid, formic acid, etc.
You can convert it into BOC and obtain the desired object. Furthermore, in the synthesis of the following compounds, etc., they can also be produced by the following synthetic route. (Synthesis example) Example 1 15 ml of methylene chloride containing 3.2 g of bromine is added dropwise into 20 ml of methylene chloride containing 1.7 g of diketene cooled to −30° C. and stirred for 15 minutes. Next, 5 g of 7-aminocephalosporanic acid,
Add the above solution containing 3-oxobutyryl bromide to 70 ml of methylene chloride to which 4 g of triethylamine has been added while keeping the solution at -30°C. The reaction solution was allowed to react for 1 hour while being gradually heated to 20°C. Next, the solvent was distilled off, the residue was shaken with 50 ml of ethyl acetate and 50 ml of 5% hydrochloric acid, the ethyl acetate layer was dried over anhydrous magnesium sulfate, the ethyl acetate was distilled off, and recrystallization was performed from ether. , 3.6 g of 7-(4-bromo-3-oxobutyrylamino)cephalosporanic acid are obtained. next,
Add 0.6g of thiourea and 0.66g of sodium bicarbonate to water.
100ml, dissolved in 50ml of tetradrofuran, 7-(4
3.6 g of -bromo-3-oxobutyrylamino)cephalosporanic acid is added and the reaction is carried out at 20°C for 1 hour. When the reaction solution is concentrated to 1/3 and allowed to cool, crystals precipitate and are separated to obtain 2.4 g of 7-[2-(2-aminothiazol-4-yl)acetamido]cephalosporanic acid. Next, this 7-[2-(2-aminothiazole-
4-yl)acetamido]cephalosporanic acid
2.4 g, sodium hydrogen carbonate 3.6 g, and 1.8 g of Z-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole were added to 100 ml of water, and the reaction system was heated at 65°C under a nitrogen atmosphere. , carry out the reaction for 5 hours. During this time, the pH of the reaction solution is controlled at 6.4 to 6.7. Next, the reaction solution is concentrated, and then isolated and purified by XAD-column chromatography to obtain 1.3 g of the target product. The target product was confirmed by NMR.
(Using DMSO− _d6 )

【table】

Table Example 2 4.5 g of furanglioxylic acid are placed in 50% alcohol and 3.1 g of methoxyamine hydrochloride dissolved in 10 ml of water are added to this solution. Then 20
While keeping the mixture at 0.degree. C., diluted caustic soda solution is added to adjust the pH to 4 to 5, and the mixture is stirred at 20.degree. C. for 15 hours to carry out the reaction. The alcohol was distilled off under reduced pressure, and the reaction solution was
% caustic soda solution and wash with ether, and the aqueous phase is brought to pH 2 with concentrated hydrochloric acid. Next, the mixture is extracted with ethyl acetate, dried over anhydrous magnesium sulfate, and ethyl acetate is distilled off under reduced pressure to obtain an oily product. Recrystallization from toluene yields syn-α-methoxyimino-2-furyl acetic acid.
Obtain 1.2g. Next, 0.6 g of sodium is added to 40 ml of methanol, and once the sodium has completely dissolved, the mixture is cooled to 3°C and 10 ml of a methanol solution containing 1.2 g of syn-α-methoxyimino-2-furylacetic acid is added. After stirring at 20°C for 20 minutes and distilling off the solvent, the residue was thoroughly dried. Syn-α- obtained here
0.65g of sodium methoxyfuryl acetate in benzene
Suspend in 30 ml, add 0.3 ml of oxalyl chloride, stir at 25°C for 30 minutes, and then distill off benzene under reduced pressure to obtain acid chloride.
After dissolving this in 15ml acetone, 0.8g of 7-
Acetone solution of acid chloride is added to a solution of aminocephalosporanic acid, 0.7 g of sodium bicarbonate, 5 ml of acetone, and 30 ml of water, and stirring is continued while maintaining the pH at 30 mm at 20°C. After the reaction is completed, adjust the pH to 2 with 6N hydrochloric acid, and then apply the XAD-column (manufactured by Organo).
By purification, 0.8 g of 7-α-methoxyiminofuryl acetamidocephalosporanic acid can be obtained. Next, 0.8 g of this compound, 2-mercapto-5
-(2-amino-2-carboxy)ethyl-1,
3,4-thiadiazole 0.5g, bicarbonate of soda 0.5
g in 40 ml of water, under nitrogen atmosphere, pH = 6.0~
6.5, carry out the reaction at 60°C for 5 hours. After the reaction is complete, adjust the pH of the reaction solution to 2 with 6N hydrochloric acid.
After distilling off some of the water, the target product 7-(α-methoxyiminofuryl acetamide)-3-[5-(2
-amino-2-carboxy)ethyl-1,3,4
-thiadiazol-2-ylthiomethyl]-3-
0.5 g of cefem-4-carboxylic acid is obtained. The target product was confirmed by NMR.
(Using DMSO-d ₆ and trifluoroacetic acid)

【table】

[Table] Example 3 5 g of 2-methoxyimino-2-(2-chloroacetylamido-4-thiazolyl)acetic acid was added to 20 ml of thionyl chloride, and the reaction was carried out at 40°C for 30 minutes. After the reaction is complete, thionyl chloride is distilled off under reduced pressure, and the residue is dissolved in 20 ml of acetone. Next, 6 g of 7-aminocephalosporanic acid, 4.8 g of sodium bicarbonate
The acid chloride obtained by the above method was added dropwise to a solution prepared by dissolving G in 30 ml of water and 5 ml of acetone while maintaining the pH at 7 at 5 to 10°C, and the mixture was stirred for 40 minutes. After the reaction was completed, the reaction solution was adjusted to pH 2 with 6N hydrochloric acid, acetone was distilled off, water was partially distilled off, concentrated, and purified using an XAD- column, resulting in 7β-[(Z) 3.9 g of -2-(2-chloroacetamido-4-thiazolyl)-2-(methoxyimino)acetamide]cephalosporanic acid are obtained. Next, this product was dissolved in 30 ml of water, 1 g of thiourea was stirred at 20°C for 6 hours, and the reaction solution was mixed with XAD-
The dechloroacetylated product is separated and purified using a column. The obtained 7β-[(Z)-2-(2-amino-4-thiazolyl)-2-(methoxyimino)acetamide]cephalosporanic acid 1.5 g, sodium hydrogen carbonate 0.7 g, 2-mercapto-5-( 0.9 g of 2-amino-2-carboxy)ethyl-1,3,4-thiadiazole was added to 50 ml of water, and the reaction was carried out at 65° C. for 4 hours while controlling the pH to 6.2 to 6.5 under a nitrogen atmosphere. After the reaction is completed, pH is adjusted with 6N hydrochloric acid.
After concentration, purification is performed using an XAD-column. 7β-[(Z)-2-(2-amino-
4-thiazolyl)-2-(methoxyimino)acetamide]-3-[5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole-2-
0.9 g of ylthiomethyl]-3-cephem-4-carboxylic acid was obtained. The target product was confirmed by NMR.
(Using DMSO-d ₆ and trifluoroacetic acid)

【table】

【table】

[Table] Example 4 7-[(Z)-2-(2-aminothiazole-4-
yl)-2-(2-carboxyprop-2-oximino)acetamidocephalosporanic acid 3.5g
, 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole
150 ml of an aqueous solution containing 1.8 g and 4.6 g of sodium hydrogen carbonate was reacted at 65° C. for 5 hours in a nitrogen atmosphere. During this time, the pH of the reaction solution is controlled at 6.3 to 6.8. After the reaction was completed, part of the water was distilled off, the residue was concentrated, and then isolated and purified by XAD-column chromatography to obtain 2.1 g of the target product. The target product was confirmed by NMR.
(Using DMSO-d ₆ and trifluoroacetic acid)

【table】

【table】

[Table] ｜
COOH
Example 5 4 g of tetrazole acetic acid was placed in 30 ml of thionyl chloride, 1 ml of dimethylformamide was added, and 1 ml of dimethylformamide was added.
Boil at reflux for an hour. Next, thionyl chloride is distilled off under reduced pressure, and the residue is dissolved in 10 ml of acetone. Next, add 8.5 g of 7-ACA to 70 ml of water and 70 ml of acetone.
and add 7.9 g of sodium hydrogen carbonate to make a homogeneous solution. The above acetone solution of tetrazole acetate chloride was added dropwise to this solution under ice cooling, and the reaction was carried out for 1 hour. After the reaction was completed, 1N HCl
After adjusting the pH to 3 and distilling off the acetone, add ethyl acetate.
Extract with 100ml, wash the ethyl acetate with water,
After drying over anhydrous magnesium sulfate, ethyl acetate was distilled off to obtain 5.2 g of 7-[1-(1H)tetrazolylacetamide]cephalosporanic acid. A similar product was obtained in condensation of 7-ACA with the triethylamine salt after conversion of tetrazole acetic acid into the p-nitrophenyl ester. Next, 2-mercapto-5-(2-amino-2
3.6 g of -carboxy)ethyl-1,3,4-thiadiazole and 3.0 g of sodium hydrogen carbonate were added to 30 ml of water, and further 5.2 g of 7-[1-(1H)-tetrazolylacetamide]cephalosporanic acid was added.
The reaction is carried out at 60°C for 6 hours. Meanwhile, PH
The reaction is carried out under a nitrogen atmosphere while controlling the conditions as described in 6.4. After the reaction is completed, the solution is heated, some of the water is distilled off, and the solution is purified by XAD-column chromatography. 7-[1-(1H)tetrazolylacetamide]-
3.2 g of 3-[5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazol-2-ylthiomethyl]-3-cephem-4-carboxylic acid was obtained. The target product was confirmed by NMR.
(Using DMSO-d ₆ and trifluoroacetic acid)

【table】

[Table] Example 6 7-[(Z)-2-(2-aminothiazole-4-
yl)-2-carboxymethoxyiminoacetamide]-3-acetoxymethyl-3-cephem-
4-carboxylic acid 3.0 g, 2-mercapto-5-(2
-amino-2-carboxy)el-1,3,4-
Thiadiazole 1.6g, sodium bicarbonate 4.5g
After dissolving in 70ml of water, heat at 65℃ under nitrogen atmosphere.
The reaction was carried out for 5 hours. During that time, the pH of the reaction solution was 6.3.
Control to ~6.7. After the reaction was completed, part of the water was distilled off, the residue was concentrated, and then isolated and purified by XAD-column chromatography to obtain 1.4 g of the target product. The target product was confirmed by NMR.
(Using DMSO− _d6 )

【table】

[Table] Example 7 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole
Add 2.0g of sodium bicarbonate and 4.0g of cephalotin sodium to 2.6g. The reaction system was replaced with nitrogen,
The reaction temperature was set to 65°C and the reaction was carried out for 5 hours. During this time, the pH of the reaction solution is controlled at 6.2 to 6.6. After the reaction is completed, some water is distilled off, and after concentration, XAD-
The target product is isolated and purified by column chromatography.
2.3g was obtained. The target product was confirmed by NMR.
(Using DMSO-d ₆ and trifluoroacetic acid)

【table】

[Table] Example 8 2-Mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole
Add 3.0 g of sodium bicarbonate and 3.1 g of cefapirin sodium to 2.0 g. The reaction system was replaced with nitrogen,
The reaction temperature was set to 65°C and the reaction was carried out for 7 hours. During this time, the pH of the reaction solution is controlled at 6.2 to 6.6. After the reaction is completed, part of the water in the reaction solution is distilled off, and after concentration,
It was isolated and purified by XAD-column chromatography to obtain 1.3 g of the target product. (Using DMSO-d ₆ and trifluoroacetic acid)

[Table] Example 9 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole
Dissolve 5.2g in 50ml dimethyl sulfoxide,
1,3,3-tetramethylguanidine 5.8g, t
- Add 5.4 g of butylphenyl carbonate,
The reaction is carried out for 30 hours at °C. After the reaction is complete,
Add 200 ml of water and extract with 100 ml of ethyl acetate. After adjusting the aqueous phase to PH2, add 100% ethyl acetate.
ml twice, dried over anhydrous magnesium sulfate, and ethyl acetate was distilled off, leaving a residue of 4.8
g remains. Next, 3 g of 7-ACA and 4.8 g of t-butyloxycarbonylated 2-mercapto-5-(2-amino-2-carboxy)ethyl-1,3,4-thiadiazole obtained by the above method were added to water. 100
ml, placed in 50 ml of acetone, sodium bicarbonate
Add 3.5 g and carry out the reaction at 65° C. under nitrogen atmosphere. After 6 hours of reaction, the acetone in the reaction solution was distilled off and the target product was isolated by XAD-column chromatography, yielding 2.2 g. Next, 7-amino-3- obtained by the above method
[5-(2-amino-2-carboxy)ethyl-
2.2 g of 1,3,4-thiadiazol-2-ylthiomethyl]-3-cephem-4-carboxylic acid is placed in 60 ml of tetrahydrofuran, and 1.2 equivalents of bis(trimethylsilyl)acetamide, which is a trimethylsilylation agent, is added. Next, 0.6 g of 2-thienyl acetic acid and 1.0 g of N,N-dicyclohexylcarbodiimide were added to the reaction system, and the mixture was allowed to react at 15°C for 10 hours. Separate the sediment. After adding 10 ml of water to the solution, the solvent was distilled off under reduced pressure, and the residue was dissolved in 60 ml of formic acid.
The reaction was carried out at ℃ for 3 hours, and the formic acid was distilled off. When ether is added to the oily residue, crystals precipitate, which are purified by XAD column chromatography to obtain 7-(2-thienylacetamide)-3.
-[5-(2-amino-2-carboxy)ethyl-
1.4 g of 1,3,4-thiadiazol-2-ylthiomethyl]-3-cephem-4-carboxylic acid was obtained. All of the NMR chemical shifts of this product matched those obtained in Example 7.

Claims (1)

[Claims] 1 General formula () [In the formula, R ₁ is R ₂ represents hydrogen or methoxy group (provided that R ₁ , R ₂ represents only hydrogen), and R ₃ represents hydrogen, a salt with an organic base, or a physiologically acceptable metal ion. ] A cephalosporin compound and physiologically acceptable inorganic and organic salts.