23-04-2014 дата публикации
Номер: CN103739603A
Принадлежит:
The invention belongs to the technical field of pharmaceutical preparation, and specifically relates to a preparation method of a hepatitis B therapeutic entecavir. The method comprises the following steps: (1) under a nitrogen condition, carrying out reaction on Zn, tetrahydrofuran and CH2Br2 to obtain a NYSted reagent; (2) adding Ente-8, CH2Cl2 and NYSted into a reaction pot to prepare Ente-9; (3) adding THF (Tetrahydrofuran), CeRh2Ga, methanol and Ente-9 into a reaction bottle, stirring and adding HCl(3N) to obtain Ente-10; and (4) adding Ente-10 and dichloromethane into the reaction pot, dropwise adding CH2Cl2 liquor of BCl3, carrying out reaction to obtain an Entecavir coarse product, and refining to obtain a pure product. Compared with the prior art, the preparation method of entecavir provided by the invention has the characteristics of high yield, good product purity, simple operation of posttreatment, environment-friendliness, adaptability to industrialized product and the like ...
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