Production method of cimetidine

Abstract

The invention relates to a production method of cimetidine, the production method comprises the following steps: (1) reacting 2-chloroethanol with thiocyanate to prepare an intermediate (I); (2) reacting the intermediate (I) with methylamine to prepare an intermediate (II); (3) oxidizing the intermediate (II) with oxyacetic acid to obtain an intermediate (III); (4) condensing the intermediate (III) and cyanamide to obtain an intermediate (IV); and (5) condensing the intermediate (IV) and imidazole mercaptan (V) to prepare cimetidine. The production method of cimetidine is provided, the production method can avoid the environmental pollution caused by the by-product methyl mercaptan generated in the existing cimetidine production, and is simple in production process, low in production cost and suitable for industrial production.

Description

technical field

[0001] The invention relates to the technical field of biomedicine, in particular to an environment-friendly and low-cost preparation method of cimetidine. Background technique

[0002] Cimetidine is a selective H2 receptor antagonist that mainly inhibits gastric acid secretion and is used for the treatment of peptic ulcer. Since the advent of cimetidine, many technological routes have been reported at home and abroad, the purpose of which is to shorten the reaction steps, improve process conditions, eliminate environmental pollution, and reduce production costs. At present, large-scale production of cimetidine at home and abroad mostly adopts the following process route:

[0003]

[0004] The disadvantage of this route is that the total yield is low, about 46%, and produces methyl mercaptan as a by-product, which has a foul smell and pollutes the environment. Japanese patent JP82-56465 reports the method of condensing phenol, cyanogen chloride and cyana...

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