A kind of synthetic method of 2-(trimethylsilyl) ethoxymethyl chloride

Abstract

The invention provides a method for synthesizing 2-(trimethylsilyl)ethoxymethyl chloride. The method includes the following steps: (1) Chloromethylation reaction: take bromoethanol, n-hexane, paraformaldehyde, and concentrated sulfuric acid, add them to the reaction bottle, start stirring, cool the system to -5-0°C, and feed HCL gas , until the raw material is less than 5%, stop the ventilation, and carry out post-reaction treatment to obtain the chloromethylated intermediate; (2) Substitution reaction: take tetrahydrofuran, add it to the reaction bottle, start stirring, cool to 15 ° C, and take n-butylmagnesium chloride in turn 1. Add 1L of n-butyllithium into the reaction solution, keep the internal temperature below 25°C, after the addition is complete, keep warm at 20-25°C and stir, take the chloromethylated intermediate prepared in step (1), and slowly add it dropwise to the reaction solution In the solution, after dropping, keep warm at 20-30°C for reaction, take trimethylchlorosilane, slowly add it dropwise to the reaction solution, keep the temperature below 30°C, after dropping, keep warm at 20-30°C for reaction, the reaction solution is concentrated under reduced pressure, The organic solvent and the crude product are recovered, and the crude product is rectified by a water pump to obtain the product. The invention has lower cost, higher yield and convenient and stable post-treatment.

Description

Technical field: [0001] The invention relates to a synthesis method of 2-(trimethylsilyl)ethoxymethyl chloride, which belongs to the technical field of pharmacy. Background technique: [0002] 2-(Trimethylsilyl)ethoxymethyl chloride (SEM-Cl), as a commonly used organosilicon protective agent, is favored for its functional selectivity, and is an important intermediate in organic synthesis. It is used in the synthesis of medicine, biology and pesticides all play an important role. However, it is expensive, not easy to store, and not high in purity. It has always been the concern of producers and users, and it is a problem that needs to be solved urgently. [0003] The scheme commonly adopted in the prior art is relatively single, and the key intermediate of the product, trimethylsilyl alcohol, is used as the main intermediate, and the final product is obtained through chloromethylation. Trimethylsilyl ethanol has the following synthetic methods: [0004] (1) Using ethyl 2-b...

AI Technical Summary

Problems solved by technology

However, there will still be water production during the first step of the reaction, which will destroy the intermediate, generate impurities, and reduce the yield.

In the second step of replacement, when butyllithium is used alone, the alkalinity is too strong, and there will be a large amount of impurities replaced by chlorine, which will seriously affect the yield and purity of the product.

The reaction is violent, it is difficult to control, and the cost of lithium aluminum hydride is very high, the operation is dangerous, and the post-processing is difficult

The entire cost of this process is very high, and the reaction is dangerous and difficult to control, so it has been abandoned abroad

The raw material chloromethyltrimethylsilane used in the second method is expensive and the cost is higher

However, the product is unstable under acidic conditions, so that the total yield of the product prepared by this process is not high, the purity is not high, and it is not easy to store

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