JPH042596B2 - - 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 (). General formula () [In the formula, R ₁ is

[expression] or

[Formula] R ₂ represents hydrogen or a methoxy group (provided that R ₁ is (in which case R ₂ represents only hydrogen), 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 is a novel cephalosporin having an S bond at histidine at the 3rd position,
These cephalosporins are effective against Gram-positive bacteria,
It also has high antibacterial activity against Gram-negative bacteria and high stability against β-lactamases produced by various Gram-negative bacteria.
The histidine group can be used in any of the D, L, and DL forms. 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] Compared to cefotaxime, compound () is characterized by being less affected by the amount of inoculated bacteria. Next, a major feature of compound () is that it has extremely low toxicity, and exhibits particularly low toxicity among third-generation cephalosporins. Acute toxicity studies of this compound in mice showed an LD ₅₀ of 10-12 g/Kg upon intraperitoneal administration. In addition, the blood concentration of compound () during intravenous injection is
Compared to the third-generation cephalosporins LMOX (latamoxef), CTX (cefotaxime), CZX (ceftizoxime), and CPZ (cefoperazine), the first
As shown in the figure, it was discovered that it has the major characteristics of extremely high blood concentration and excellent persistence.
The figure shows the results obtained using Wistar rats, 7 weeks old, at a dose of 20 mg/Kg. Thus, it has been found that the 3-position histidine derivative has not only strong antibacterial activity but also low toxicity and excellent effects in terms of blood concentration and persistence. As mentioned above, Esherichia coli, Klebsiella
pneumoneae, Shigella sonnei, Enterobacter
It was found that it exhibits extremely strong antibacterial activity against cloacas, Serratia marcescens, indole-positive Proteus, etc. Furthermore, the MIC of the following compound () is as follows.

【table】

[Table] Next, the MIC of the following compound () is as follows.

[Table] Next, the blood concentrations of Compounds () and () after intravenous injection were measured using the same method as for Compound (), and compared with cefapirin and cephalothin, respectively. The results are shown in Figures 2 and 3. Indicated. As seen in the above examples of compounds () () (), the introduction of histidine at the 3-position greatly contributes to the antibacterial activity. Furthermore, the compound (),
As seen in the blood concentrations during intravenous injection of () and (), the introduction of histidine into the cephalosporin skeleton has a significant effect on high blood concentrations and persistence. Additionally, as seen in the example below,
Introducing histidine into the 3rd position improves intestinal absorption. For example, when comparing the maximum blood concentrations of cefotaxime and Compound (2) after oral administration in 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, regarding the method for synthesizing the compound of the present invention, the compound 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 -COOH is reacted with an activated form, such as an active ester mixed acid anhydride. There is a method in which the 7-ACA derivative is converted into a 7-ACA derivative and then reacted with a 7-ACA derivative. Moreover, R ₁
-It can also be reacted after being made into an acid chloride like 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. In addition, in reactions such as acid chloride,
It is also possible to use aqueous systems. Next, the conversion reaction of the acetoxymethyl group at the 3-position with thiolhistidine is carried out in water or a mixed solvent such as methanol, acetone, etc., using sodium hydrogen carbonate or triethylamine as a base, and the pH of the reaction system is adjusted to 6 to 6. 1 to 1 in the range of 30 to 100℃ while controlling around 7.
The 3-position conversion reaction can be carried out by reacting for 20 hours, preferably 2 to 10 hours. During this time, the reaction system is preferably under a nitrogen atmosphere. Next, regarding the route (), to give one example, after protecting the amino group of thiolhistidine and, for example, t-butyloxycarbonylation, 7-
The acetoxymethyl group at the 3-position of ACA (or its derivatives) is PH
The reaction is carried out at 30 to 100°C for 1 to 20 hours while controlling the temperature to 6 to 7. The 4-position carboxyl group and the 3-position histidine carboxyl group of the obtained compound 7-ACA derivative are trimethylsilylated, or they are left free and treated with RCOOH or its carboxylic acid activated form (e.g., active ester, mixed acid anhydride). (acid chloride). Afterwards, it is decomposed by trifluoroacetic acid.
You can convert it into BOC and obtain the desired object. Example 1 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-thiol-L-
0.5 g of histidine and 0.5 g of sodium bicarbonate are added to 40 ml of water, and the reaction is carried out at 60° C. for 5 hours under a nitrogen atmosphere while maintaining the pH at 6.0 to 6.5. After the reaction, the pH of the reaction solution was adjusted to 2 with 6N hydrochloric acid, some of the water was distilled off, and the target product 7-(α-methoxyiminofuryl acetamide)-3 was purified using an XAD- column. 0.5 g of -[(2'-amino-2'-carboxy)ethylimidazol-2-ylthiomethyl]-3-cephem-4-carboxylic acid is obtained. The desired product was confirmed by NMR measurement (DMSO/trifluoroacetic acid).

【table】

[Table] Example 2 15 ml of methylene chloride containing 3.2 g of bromine is dropped 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 tetrahydrofuran, 7-
Add 3.6 g of (4-bromo-3-oxobutyrylamino)cephalosporanic acid, and react 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-Aminothiazol-4-yl)acetamide] 2.4 g of cephalosporanic acid, 3.6 g of sodium bicarbonate, 2.0 g of 2-thiol-L-histidine
was added to 100 ml of water, and the reaction system was heated at 65℃ under a nitrogen atmosphere.
The reaction is carried out for 5 hours. During this time, the pH of the reaction solution is 6 to 6.7.
control. Next, after concentrating the reaction solution,
Isolation and purification by XAD-column chromatography yields 1.3 g of the desired product. The target product was confirmed by NMR.
(DMSO, trifluoroacetic acid)

[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]cephalosboranic acid
Add 1.5 g, sodium hydrogen carbonate 0.7 g, and 2-thiol-L-histidine 0.8 g to 50 ml of water, and add 65 ml of water while controlling the pH to 6 to 6.5 under a nitrogen atmosphere.
The reaction is carried out for 4 hours at °C. After the reaction is completed, the pH is adjusted to 2 with 6N hydrochloric acid, concentrated, and purified using an XAD-column. 7β-[(Z)-2-(2-amino-4-thiazolyl)-2-(methoxyimino)acetamide]-3-[(2'-carboxy)ethylimidazol-2-ylthiomethyl]-3-cephem-4 -0.9 g of carboxylic acid was obtained. Confirmation that it was the desired product was performed by NMR (trifluoroacetic acid).

【table】

[Table] Example 4 3.3 g of 2-thiol-L-histidine and 4.0 g of sodium bicarbonate are dissolved in 150 ml of water by heating at 50°C, and then 3.7 g of cephalothin sodium is added to this solution. The reaction system was purged with nitrogen, the reaction temperature was raised 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 to 6.5. After the reaction, part of the water was distilled off, concentrated, and isolated and purified by XAD- column chromatography to obtain the desired product 2.4.
I got g. The target product was confirmed by NMR (DMSO, trifluoroacetic acid).

【table】

[Table] Example 5 5.0 g of 2-thiol-L-histidine and 9.1 g of sodium bicarbonate are dissolved in 150 ml of water by heating at 50°C, and then 6.0 g of cefapirin sodium is added to this solution. The reaction system was purged with nitrogen, the reaction temperature was raised 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 to 6.5. After the reaction, excess 2-thiol-L-histidine was removed by filtration, part of the water was distilled off and concentrated,
It was isolated and purified by XAD-column chromatography to obtain 2.6 g of the target product. The target product was confirmed by NMR (DMSO, trifluoroacetic acid).

【table】

【table】

[Table] Example 6 7-[(Z)-2-(2-aminothiazole-4-
yl)-2-(2-carboxyprop-2-oximino)acetamidocephalosporanic acid 3.5g
was added to 150 ml of an aqueous solution containing 2.5 g of 2-thiol-L-histidine and 4.6 g of sodium bicarbonate, and the reaction was carried out at 65° C. for 5 hours under a nitrogen atmosphere. During this time, the pH of the reaction solution is controlled at 6 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 (DMSO, trifluoroacetic acid).

[Table] ｜
COOH

【table】

[Table] Example 7 4.7 g of thiolhistidine was dissolved in 50 ml of dimethyl sulfoxide, 5.8 g of 1,1,3,3-tetramethylguanidine and 5.4 g of t-butylphenyl carbonate were added, and the reaction was carried out at 50°C for 30 hours. Let's do it. After the reaction is complete, add 200 ml of water and extract with 100 ml of ethyl acetate. After the aqueous phase was brought to pH 2, it was further extracted twice with 100 ml of ethyl acetate, dried over anhydrous magnesium sulfate, and the ethyl acetate was distilled off, leaving 4.6 g of a residue. Next, 3 g of 7-ACA and 4.6 g of t-butyloxycarbonylated thiolhistidine obtained by the above method were placed in 100 ml of water and 50 ml of acetone, 3.5 g of sodium bicarbonate was added, and the mixture was heated at 65°C under a nitrogen atmosphere. The reaction is carried out at After 6 hours of reaction, the acetone in the reaction solution was distilled off and the target product was isolated using XAD- column chromatography, resulting in 2.1
g is obtained. Next, 7-amino-3- obtained by the above method
[(2'-t-butyloxycarbonylamino-2'-
2.1 g of carboxy)ethylimidazol-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 melimethylsilylating 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.
-[(2'-amino-2'-carboxy)ethylimidazol-2-ylthiomethyl]-3-cephem-
1.3 g of 4-carboxylic acid was obtained. All of the NMR chemical shifts of this product matched those obtained in Example 4.

[Brief explanation of drawings]

Figure 1 is a graph showing the blood concentration of compound () and third-generation cephalosporin after intravenous injection;
The figure is a graph showing the blood concentration of compound (2) and cephapirin after intravenous injection, and FIG. 3 is a graph showing the blood concentration of compound (2) and cephalothin after intravenous injection.

Claims (1)

[Claims] 1 General formula () [In the formula, R ₁ is [Formula] or [Formula] R ₂ represents hydrogen or a methoxy group (provided that R ₁ (in which case R ₂ represents only hydrogen), 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.