A kind of preparation method of 4-methyl-5-ethoxy oxazole

A technology of ethoxyoxazole and ethoxy, which is applied in organic chemistry, products, reagents, etc., can solve the problems of low solubility, high energy consumption, long time, etc., and achieves simple and safe process operation, good process stability, The effect of mild reaction conditions

CN109627226BActive Publication Date: 2022-05-31迪嘉药业集团股份有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2022-05-31
Patent Text Reader

Abstract

The invention relates to a preparation method of 4-methyl-5-ethoxyxazole, a key intermediate of vitamin B6, and belongs to the technical field of preparation of raw materials. The preparation method of 4-methyl-5-ethoxyxazole described in the present invention, first in the hydrolysis reaction kettle, drop into 4-methyl-5-ethoxyl-1,3-oxazole-2 sequentially in a certain proportion ‑Ethyl carboxylate, toluene, drinking water and sodium hydroxide, stir and keep warm for reaction; separate liquid, use hydrochloric acid to adjust the pH value of the aqueous phase in the range of 1.0‑2.5; add organic solvent to the system obtained in the second step, 30‑50 °C Control the temperature and react until no carbon dioxide is released; after decarboxylation, adjust the pH value to ≥9.0, separate the liquids, and distill the organic phase under reduced pressure to obtain the intermediate 4-methyl-5-ethoxyoxazole. The technological operation is simple and safe, and the industrial production is easy.
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Description

A kind of preparation method of 4-methyl-5-ethoxyoxazole technical field The present invention relates to a kind of preparation method of the key intermediate 4-methyl-5-ethoxyoxazole of vitamin B6, belong to The technical field of raw medicine preparation. Background technique 4-methyl-5-ethoxyoxazole is one of the main intermediates of synthesizing vitamin B6. Its production process mainly adopts What is: 4-methyl-5-ethoxy-1,3-oxazole-2-ethyl carboxylate carries out alkali hydrolysis-acid precipitation-decarboxylation-neutralization-distillation. existing technology During the operation, after the alkali hydrolysis of ethyl 4-methyl-5-ethoxy-1,3-oxazole-2-carboxylate, the liquid is separated and the water layer is retained. The water layer was evaporated under reduced pressure Ethanol was removed by distillation, then acid precipitation and heating decarboxylation. Chinese patent CN102321043A, discloses 5-ethoxy-4-methyl-1,3-oxazole-2-carboxylic acid ethyl est...

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