Preparation method of cefoxitin derivative
The enzymatic hydrolysis and silylation protection method addresses synthesis challenges by achieving high-purity cefoxitin derivatives with reduced solvent use and environmentally friendly conditions, enhancing the efficiency and economy of the production process.
Patent Information
- Application Number
- CN202310764516.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-27
- Publication Date
- 2024-12-27
AI Technical Summary
Existing methods for synthesizing cefoxitin derivatives face challenges such as incomplete reactions due to steric hindrance and electron donating ability, leading to impurities and inefficiencies in the production process.
A method involving enzymatic hydrolysis of a cefoxitin intermediate to remove the 2-thiophene acetyl group, followed by silylation protection and reaction with 2-thiophenecarbonyl chloride, using immobilized penicillin acylase and controlled conditions, to achieve a nearly quantitative reaction.
The method results in a high-purity cefoxitin derivative with reduced organic solvent use, environmentally friendly processes, and mild conditions, providing a convenient synthesis for similar compounds.
Smart Images
Figure BDA0004306430530000011 
Figure BDA0004306430530000012 
Figure BDA0004306430530000021
Abstract
Description
Technical Field
[0001] The invention belongs to the field of pharmaceutical chemical technology synthesis, and specifically relates to a method for preparing a cefoxitin derivative. Background Art
[0002] Cefuroxetine sodium is a broad-spectrum cephalosporin antibiotic widely used in clinical practice. Related derivatives of Cefuroxetine sodium will be generated during the synthesis process. For example, the compound 3-(acetoxymethyl)-7-methoxy-8-oxo-7-(thiophene-2-carboxamide)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid is one of the derivatives that may be produced during the synthesis process of Cefuroxetine sodium. By studying the synthesis method of this compound, it is possible to provide a reference substance or positioning substance for the study of drug impurities, and also provide a way of thinking for the development of new cephalosporin products. Summary of the invention
[0003] The purpose of the present invention is to provide a method for preparing a cefoxitin derivative.
[0004] In order to achieve the above object, the present invention adopts the following technical scheme:
[0005] A preparation method of a cefoxitin derivative, comprising taking a cefoxitin intermediate as a starting material, removing a 2-thiophene acetyl group by enzymatic hydrolysis to obtain a cefoxitin derivative intermediate, and then reacting the cefoxitin derivative intermediate with 2-thiophenecarbonyl chloride after silylation protection to obtain a cefoxitin derivative;
[0006] Wherein, the structural formula of the cefoxitin intermediate is
[0007]
[0008] The structural formula of the cefoxitin derivative intermediate is
[0009]
[0010] The structural formula of the cefoxitin derivative is
[0011]
[0012] Preferably, the enzyme is immobilized penicillin acylase.
[0013] Preferably, the feed mass ratio of the cefoxitin intermediate to the enzyme is (1-2):1, for example, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1 or 2:1, etc.
[0014] Preferably, the temperature of the enzymatic hydrolysis is controlled to be 10-35°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, etc.
[0015] Furthermore, the temperature of the enzymatic hydrolysis is controlled to be 25-30°C.
[0016] Preferably, the pH of the enzymatic hydrolysis is controlled to be 5.5 to 9.5, for example, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, etc.
[0017] Furthermore, the pH of the enzymatic hydrolysis is controlled to be 6.5-7.5.
[0018] Preferably, the cefoxitin intermediate and the enzyme are subjected to a hydrolysis reaction in the presence of water, wherein the concentration of the cefoxitin intermediate in the hydrolysis system is controlled to be 10-30%, for example, 10%, 13%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, etc.
[0019] Furthermore, the concentration of the cefoxitin intermediate in the hydrolysis system is controlled to be 15-20%.
[0020] Preferably, the preparation method further comprises the steps of filtering, washing, adjusting the pH, and temperature-controlled crystallization of the hydrolysis system after the enzymatic hydrolysis is completed.
[0021] In some embodiments, the steps of filtering, washing, adjusting the pH, and controlling the temperature to crystallize the hydrolysis system specifically include filtering and washing with purified water after the enzymatic hydrolysis is completed, adjusting the pH of the filtrate with hydrochloric acid, controlling the temperature to 15-20°C for crystallization, continuing to adjust the pH to 3.5-4.0, controlling the temperature to 5-10°C, stirring, filtering, washing, and drying.
[0022] Preferably, the molar ratio of the cefoxitin derivative intermediate to the 2-thiophenecarbonyl chloride is 1:(1-1.4), for example, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, etc.
[0023] Preferably, the temperature of the reaction of the cefoxitin derivative intermediate after silylation protection with 2-thenoyl chloride is controlled not to exceed 15°C.
[0024] Furthermore, the reaction temperature is -5 to 15°C, for example, -5°C, 0°C, 5°C, 10°C, 15°C, etc.
[0025] Preferably, the specific step of subjecting the cefoxitin derivative intermediate to silylation protection is: using a silylation protection reagent and the cefoxitin derivative intermediate to carry out a silylation protection reaction, wherein the feeding molar ratio of the silylation protection reagent to the cefoxitin derivative intermediate is (1.2-2):1, for example, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, etc.
[0026] In some embodiments, the silylation protecting agent is N,O-bis(trimethylsilyl)acetamide.
[0027] Preferably, the silylation protection reaction temperature is controlled to be 10-35°C, such as 10°C, 15°C, 20°C, 25°C, 30°C or 35°C.
[0028] Preferably, the preparation method further comprises a post-treatment step, wherein the post-treatment step comprises the steps of hydrolyzing, adjusting the pH, decolorizing, filtering, washing and drying the reaction system after the reaction is completed.
[0029] In some embodiments, after the reaction is completed, the temperature is controlled not to exceed 10° C., water is added and stirred for hydrolysis, the layers are separated, the pH of the organic phase is adjusted with an aqueous sodium bicarbonate solution, the temperature is controlled, the layers are separated, activated carbon is added to the aqueous phase for decolorization, the phase is filtered, the pH is adjusted to 2.2-2.6 with hydrochloric acid, the phase is filtered, washed, and dried.
[0030] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:
[0031] The invention provides a method for preparing a cefoxitin derivative. The cefoxitin derivative prepared by the preparation method has high purity, and the whole process is green and environmentally friendly, reduces the use of organic solvents, is easy to operate, and has mild conditions. It is an economical and applicable new method, and also finds a convenient synthesis method for the synthesis of similar compounds in the future. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 It is the mass spectrum of compound ① in Example 1. DETAILED DESCRIPTION
[0033] The present invention is further described below in conjunction with the examples. However, the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.
[0034] The present invention relates to a cefoxitin derivative (3-(acetoxymethyl)-7-methoxy-8-oxo-7-(thiophene-2-carboxamide)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid), namely the following compound ①. Since the 7-group is 2-formylthiophene acid, we found in the research process that if 2-thenoylcefoxitin acid is formed and then a conventional methoxy substitution method similar to that in the process of preparing cefoxitin acid is used, the methoxy substitution cannot be completely reacted due to the influence of steric hindrance and electron donating ability.
[0035] The inventor creatively uses a cefoxitin intermediate compound (3-(acetoxymethyl)-7-methoxy-8-oxo-7-(2-(thiophen-2-yl)acetylamino)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid cyclohexylamine salt, i.e., the following compound ②) as a starting material to synthesize a cefoxitin derivative, removes the 2-thiopheneacetyl group of the 7-group by enzymatic hydrolysis to obtain a cefoxitin derivative intermediate (i.e., the following compound ③), and after enzymatic hydrolysis, the 2-thiopheneacetyl group is substantially completely removed, and then reacts with 2-thiophenecarbonyl chloride, and acylation at the 7-position is performed again, and especially after silylation protection, the reaction with 2-thiophenecarbonyl chloride is also nearly quantitatively completed. The whole process is green and environmentally friendly, reduces the use of organic solvents, is easy to operate, and has mild conditions. It is an economical and applicable new method, and also finds a convenient synthesis method for the synthesis of similar compounds in the future.
[0036] In addition, the cefoxitin derivative is one of the possible derivatives of cefoxitin sodium in the synthesis process, and is also an impurity that may exist in cefoxitin sodium. Its preparation can provide a reference substance or positioning substance for the study of drug impurities, and also provide a way of thinking for the development of new cephalosporin products. The present invention is further discussed below in conjunction with specific embodiments.
[0037] Unless otherwise specified, the structural formula of the compound ① involved in the following examples is:
[0038]
[0039] The structural formula of compound ② is:
[0040]
[0041] The structural formula of compound ③ is:
[0042]
[0043] Example 1
[0044] Preparation of compound ③:
[0045] In a 1000mL round-bottom flask, 60g (0.11mol) of compound ②, 38g of immobilized penicillin acylase (IPA-C) (manufacturer: Guangzhou Yuanheng Technology Co., Ltd.), and 300mL of purified water were added. The temperature was controlled at 25°C to 30°C. A 5% ammonia solution was used to control the pH value to 7.0 to 7.5 for hydrolysis reaction. As the reaction proceeded, the pH value decreased. 5% ammonia solution was continuously used to control the pH value to 7.0 to 7.5 for enzymatic hydrolysis reaction. The reaction was carried out until the pH value was basically stable. The reaction was completed in about 3 to 4 hours, filtered, washed with 50mL of purified water, and the pH value of the filtrate was adjusted with 2mol / L hydrochloric acid. The temperature was controlled at 15°C to 20°C. When turbidity appeared, the crystal was grown for 1 hour, and the pH value was continued to be adjusted to 3.5 to 4.0. The temperature was controlled at 5°C to 10°C and stirred for 1 hour. Filtered, washed with 100mL of purified water, washed with 50mL of acetone, and the filter cake was vacuum dried at 45°C to obtain 30g of compound ③ with a yield of 86.8%.
[0046] Preparation of compound ①:
[0047] Add 30g of compound ③ and 250mL of ethyl acetate to a dry 500mL round-bottom flask, control the temperature at 25℃~30℃, add 30g (0.15mol) of BSA (N,O-bis(trimethylsilyl)acetamide), stir and react until clear, about 5-6 hours, cool to 0℃~5℃, add 16g of 2-thiophenecarbonyl chloride dropwise, control the temperature and stir to react for 1 hour, after the reaction is completed, control the temperature not exceeding 10℃, add 150mL of purified water, stir and hydrolyze for 15 minutes, separate the layers, and discard the aqueous phase The organic phase was removed, the pH value was adjusted to 6.0-6.5 with 5% sodium bicarbonate aqueous solution, the temperature was controlled at 20°C-25°C, the layers were separated, 2g of activated carbon was added to the aqueous phase for decolorization for 30 minutes, filtered, the pH value was adjusted to 2.2-2.6 with 2N hydrochloric acid, filtered, washed, and dried to obtain 37.5g of compound ①, with a yield of 91.5%, a purity of 98.5%, and a mass spectrum ion peak of 353 (the relative molecular mass of compound ① is 412 minus the relative molecular mass of acetyl group is 59, which equals the mass spectrum ion peak of 353). The spectrum is shown in FIG. Figure 1 shown.
[0048] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for preparing a cefoxitin derivative, characterized in that: The cefoxitin intermediate is used as a starting material, and the 2-thiophene acetyl group is removed by enzymatic hydrolysis to obtain a cefoxitin derivative intermediate. The cefoxitin derivative intermediate is then protected by silylation and reacted with 2-thiophenecarbonyl chloride to obtain a cefoxitin derivative. The structural formula of the cefoxitin intermediate is and / or The structural formula of the cefoxitin derivative intermediate is The structural formula of the cefoxitin derivative is 2. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The enzyme is immobilized penicillin acylase.
3. The method for preparing a cefoxitin derivative according to claim 1 or 2, characterized in that: The feed mass ratio of the cefoxitin intermediate to the enzyme is (1-2):
1.
4. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The temperature of the enzymatic hydrolysis is controlled to be 10-35°C and / or the pH is controlled to be 5.5-9.
5.
5. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The cefoxitin intermediate and the enzyme are subjected to a hydrolysis reaction in the presence of water, wherein the concentration of the cefoxitin intermediate in the hydrolysis system is controlled to be 10-30%.
6. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The preparation method also includes the steps of filtering, washing, pH adjustment, and temperature-controlled crystallization of the hydrolysis system after the enzymatic hydrolysis is completed.
7. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The molar ratio of the cefoxitin derivative intermediate to the 2-thenoyl chloride is 1:(1-1.4); and / or, The reaction temperature was controlled not to exceed 15°C.
8. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The specific step of silylation-protecting the cefoxitin derivative intermediate is: using a silylation protection reagent and the cefoxitin derivative intermediate to carry out a silylation protection reaction, wherein the feeding molar ratio of the silylation protection reagent to the cefoxitin derivative intermediate is (1.2-2):
1.
9. The method for preparing a cefoxitin derivative according to claim 8, characterized in that: The silylation protection agent is N,O-bis(trimethylsilyl)acetamide; and / or, The silylation protection reaction temperature is controlled to be 10-35°C.
10. The method for preparing a cefoxitin derivative according to claim 1, characterized in that: The preparation method further comprises a post-treatment step, wherein the post-treatment step comprises the steps of hydrolyzing, adjusting pH, decolorizing, filtering, washing and drying the reaction system after the reaction is completed.