A kind of preparation method of cyclopropylamine intermediate methyl cyclopropanate

Abstract

The invention discloses a method for preparing cyclopropylamine midbody cyclopropanecarboxylic acid methyl ester. First in a sealed reaction kettle, methanol is added dropwise into calcium carbide, togenerate calcium methoxide and acetylene; gamma-chloro methyl butyrate is added into calcium methoxide at 60-120 DEG C, the temperature is controlled to be constant in the reaction process, methanolgenerated in the process is collected, and the cyclopropanecarboxylic acid methyl ester is obtained through distillation. The method is simple in process, types of raw materials necessary for production are fewer, some of the raw materials can be reused, the yield is high, the quality is good, and the method is safe and environmentally friendly.

Description

technical field

[0001] The invention relates to the technical field of synthesis of pharmaceutical intermediates, in particular to a method for preparing a cyclopropylamine intermediate, methyl cyclopropanate. Background technique

[0002] At present, there are many technological routes for producing methyl cyclopropanate, but the main production route is that methyl γ-chlorobutyrate is dehydrochlorinated by sodium methoxide to form a ring to generate methyl cyclopropanate. The industrial sodium methoxide is a low-concentration methanol solution, so the methanol needs to be distilled during the cyclization reaction. The sodium methoxide precipitated during the treatment is easily attached to the side wall of the reactor, resulting in incomplete reaction and difficult to control the yield. The impurity content in the product is more; And when adopting sodium methylate to process methyl cyclopropanate, a large amount of methanol will circulate in the system, which will affect ...

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