Preparation method of trimethyl orthoformate

Abstract

Disclosed are high-quality trimethyl orthoformate and a preparation method of the trimethyl orthoformate. The preparation method of the trimethyl orthoformate comprises the steps of obtaining amine salt by reaction between hydrocyanic acid and carbinol and hydrogen chloride and obtaining a trimethyl orthoformate coarse product through alcoholysis; and carrying out centrifugal separation on alcoholysis reaction liquid, and refining the obtained coarse product by adding aqueous alkali. The purity of the trimethyl orthoformate product obtained with the refining method can reach to 99.6%-99.8wt%, triazine impurity content is pretty small and is only 0.001-0.06%, and particularly purification yield of the refining method is more than 90% and can reach to 96% to the maximum degree. According to the trimethyl orthoformate and the preparation method of the trimethyl orthoformate, treating agents can be obtained easily, cost is low, reaction condition is moderate, and the trimethyl orthoformate and the preparation method of the trimethyl orthoformate are particularly suitable for industrial mass production.

Description

technical field [0001] The present invention relates to a kind of preparation of organic synthesis intermediate, in particular to a kind of preparation method of trimethyl orthoformate. Background technique [0002] Trimethyl orthoformate, also known as trimethoxymethane [HC(OCH3)3], is an important intermediate in organic synthesis. In medicine, it is used to synthesize vitamin A, vitamin B1, sulfonamides, antibiotics, etc.; in coatings, it is used to dehydrate polyurethane or epoxy coatings to prevent hardening; it is also used in the synthesis of spices, and the market usage is increasing year by year. [0003] The production method of trimethyl orthoformate commonly used in the world at present is to react with nitrile, methanol and hydrogen chloride to generate hydrohalic acid imide salt, then alcoholysis and refining to obtain the trimethyl orthoformate product; wherein the refining step is Refining the alcoholysis reaction liquid, specifically performing primary dist...

AI Technical Summary

Problems solved by technology

Although the "one-pot method" is relatively simple to operate, the acidity of the salt-forming reaction solution is too strong, which is not conducive to the alcoholysis reaction, and the impurities in the salt-forming reaction directly enter the alcoholysis reaction, which increases the side reactions of the alcoholysis reaction. There are many impurities, which are not conducive to product separation. The product yield is low, and the average yield is about 60%. Alcoholysis, followed by primary distillation, purification treatment and secondary distillation and other steps to obtain trimethyl orthoformate product, wherein the imide salt obtained through the salification reaction, after the active intermediate imine salt is separated and purified, The imide salt has low acid content and few impurities, which is more conducive to alcoholysis reaction and suppression of by-products and product separation, high yield and high product purity; but in the currently disclosed two-step method, the reaction heat of the entire reaction system is relatively high, The controllability of the reaction is poor, so that the yield is unstable, and the reaction system has a large safety hazard. In addition, the reaction is not thorough enough, so that the yield of the product is low

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