- Method for producing cefdinir active ester
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The invention relates to a method for producing cefdinir active ester, and belongs to the technical field of medicine synthesis. The preparation method comprises the following steps: by taking ethyl demethylaminothioxime acid as a raw material, dissolving the ethyl demethylaminothioxime acid by utilizing organic alkali and an inert solvent, reacting, cooling, adding acetic anhydride, and continuously reacting, so as to obtain an acetylated organic amine salt solution of the demethylaminothioxime acid; dropwise adding phosphite, and adding DM by controlling the feeding time to obtain a crude product; dissolving the crude product, and crystallizing to obtain the cefdinir active ester. According to the invention, the processes of aqueous-phase acid formation and crystal water removal in the traditional process are prevented, and no waste salt or waste water is generated; the organic base serves as a hydrolytic agent and an esterification catalyst, the use amount of the ester catalyst is reduced, and the cefdinir active ester with the purity of 99.40% or above can be obtained through a DMF/ROH elution method.
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Paragraph 0040-0071
(2021/04/17)
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- Cefdinir active thioester preparation method (by machine translation)
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The invention belongs to the technical field of the preparation of the organic amine, in particular to a cefdinir active thioester of the preparation method. In order to to a ammonia [...] as raw materials, it is dissolved in the organic base with an inert solvent in the mixed solution of, for 25 - 50 °C reaction 1 - 4 is H, adding acetic anhydride, and control the pH value in the 5 - 10 for 35 - 42 °C reaction 1 - 2 H-, be acetylated to a ammonia thiophene oxime organic amine salt solution; for 10 - 35 °C dropwise DM and a phosphite composition premixed reaction, esterification reaction 0.5 - 1.5 h, cooling, filtering, obtain cefdinir active thioester. The invention process to avoid the traditional water in process [...] and to remove the crystal water of the process; organic alkali can at the same time as the hydrolytic agent and the esterification catalyst, reducing the use of the inorganic alkali, does not produce waste water waste, and the process is short, environmental protection, is conducive to large-scale production. (by machine translation)
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Paragraph 0032-0034; 0035-0037; 0038-0040
(2018/04/21)
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- Improved synthesis of Cefdinir and its polymorphic form, an antibacterial active pharmaceutical ingredient
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New methods for the preparation of Cefdinir 1 and its polymorphic form Sesqui hydrate 1a are described. The synthesis of 2-mercaptobenzothiazolyl (Z)-2-(2-amino-4-thiazolyl)-2-acetoxyiminoacetate 4 was affected by using triphenylphosphine and triethylamine, and acylation of 7-amino-3-vinylcephem-4- carboxylic acid 5 followed by deprotection with K2CO3 in the presence of ammonium chloride in the same pot yielded crude Cefdinir. Purification of crude Cefdinir through resin and treatment of the resulting wet product with trifluoroacetic acid gave highly pure TFA salt of Cefdinir 6, which on neutralization afforded 1a in excellent yield. The impurity profiling of this compound has also been discussed. Copyright Taylor & Francis Group, LLC.
- Rao, Korrapati V. V. Prasada,Dandala, Ramesh,Sivakumaran, Meenakshisunderam S.,Rani, Ananta,Naidu, Andra
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p. 2275 - 2283
(2008/02/07)
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- ALKANOYL AMIDE SOLVATES OF 2-(2-AMINOTHIAZOLE-4-YL)-2-(ACYLOXYIMINO)ACETIC ACID
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Subject of the present invention are N,N-dimethyl alkanoyl amide solvates of 2-(2-aminothiazole -4-yl)-2(acyloxyimino)acetic acid compounds of formula (I) which may be prepared in an anhydrous form. Crystalline compounds of formula I are useful in a reaction step with an activating agent in order to produce cefdinir. Additionally, a process to prepare compounds of formula I is a part of the present invention.
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Page/Page column 8
(2010/02/15)
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- TERTIARY AMINE SALTS OF 2-(2-AMINOTHIAZOLE-4-YL)-2-ACYLOXYIMINO)ACETIC ACID
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Subject of the present invention are crystalline tertiary amine salts of 2-(2-aminothiazole-4-yl)-2-(acyloxyimino)acetic acid compounds of formula (I) wherein R1, R2 and R3 independently represents unsubstituted or substituted alkyl, cyclo-alkyl or aryl, and R4 denotes acyl, which may be obtained in anhydrous form. Crystalline compounds of formula I are useful in a reaction step with an activating agent in order to produce cefdinir. Additionally, a process to prepare compounds of formula I is a part of the present invention.
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Page/Page column 11
(2010/02/15)
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- Process for preparing cefdinir
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The present invention relates to a novel process for the preparation of intermediate, 2-mercapto-benzothiazolyl (Z)-2-(2-amino-4-thiazolyl)-2-acetyloxyiminoacetate of Formula I and its use in the preparation of Cefdinir.
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