Method for preparing aminoacetaldehyde dimethyl acetal

Abstract

The invention discloses a method for preparing aminoacetaldehyde dimethyl acetal, which comprises the following steps: S1, adding a phase transfer catalyst A and vinyl acetate into a reaction flask, introducing a certain amount of chlorine while stirring, and performing heat-insulation stirring until the color of the reaction solution becomes colorless to obtain a chlorination solution; S2, dropwise adding the chlorination liquid prepared in the step S1 into methanol for reaction to prepare a chloroacetaldehyde dimethyl acetal crude product; S3, transferring the chloroacetaldehyde dimethyl acetal crude product prepared in the step S2 to an autoclave, introducing liquid ammonia, carrying out heating and pressurizing reaction, and after the reaction is finished, adding alkali to adjust the pH value; and S4, decompressing and rectifying the reaction product to obtain the target product, aminoacetaldehyde dimethyl acetal. By adopting the method, high-purity aminoacetaldehyde dimethyl acetal can be prepared, and the industrial production requirement of aminoacetaldehyde dimethyl acetal can be met.

Description

Technical field [0001] The invention relates to a method for preparing aminoacetaldehyde dimethylacetal. Background technique [0002] Amino acetaldehyde dimethyl acetal (C 4 H 12 NO 2 ), Aminoacetaldehyde dimethyl acetal, also known as aminoacetaldehyde dimethyl acetal, is a colorless liquid, often used as a pharmaceutical intermediate, such as for the effective synthesis of proline analogues from ascorbic acid through a 3-step reaction, and also used Synthesize anti-AIDS raw materials dulutvir, anthelmintic praziquantel, etc. [0003] The structural formula of aminoacetaldehyde dimethyl acetal is as follows: [0004] [0005] The traditional process of aminoacetaldehyde dimethylacetal takes a route of direct reaction between chloroacetaldehyde dimethylacetal (purity>99%) and ammonia water, and then deamination, dehydration, neutralization, distillation and rectification to obtain finished products. However, the use of chloroacetaldehyde dimethylacetal raw materials with a puri...

AI Technical Summary

Problems solved by technology

Although there are many methods for synthesizing chloroacetaldehyde dimethyl acetal, some reaction conditions are harsher, some reaction steps are cumbersome and the yield is low, and a large amount of solid waste and waste water are produced. The method for preparing chloroacetaldehyde dimethyl acetal has become an urgent problem to be solved. The problem

In addition, ammonia water is used in the reaction, resulting in the need to distill a large amount of water for post-treatment, consuming a large amount of energy and causing environmental problems

[0007] It can be seen that using high-purity chloroacetaldehyde dimethyl acetal to prepare aminoacetaldehyde dimethyl acetal, the amount of "three wastes" is relatively large, and the yield is low, which is not conducive to industrial production

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