148774-47-4Relevant articles and documents
Preparation methods of Cefditoren acid delta 3 isomer and cefditoren pivoxil delta 3 isomer
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Paragraph 0148-0175, (2019/11/12)
The invention discloses preparation methods of Cefditoren acid delta 3 isomer and cefditoren pivoxil delta 3 isomer. The cefditoren acid delta 3 isomer is prepared from the following steps that pure water and tetrahydrofuran are added in a reaction vessel, the temperature is lowered to 0-5 DEG C, a 7-ATCA delta 3 isomer and AE active ester (MAEM) are added, after adding is completed, then organicalkali is dropwise added to control pH of 8.0-8.5, the organic alkali is needed to be additionally added to keep the pH of 8.0-8.5, dichloromethane and water are added after reaction is completed, stirring and extraction are conducted, still standing and layering are conducted, a lower organic layer is discarded, the pH of an upper water layer is 3.0-3.5, stirring and filtering are conducted, andwashing and drying are conducted to obtain a product. The content of the cefditoren acid delta 3 isomer and the cefditoren pivoxil delta 3 isomer which are prepared through the preparation method canreach above 93%.
