Preparation method of ethyl 6,8-dichlorocaprylate

Abstract

A preparation method of ethyl 6,8-dichlorooctanoate belongs to the technical field of preparation of organic compound intermediates. It uses N,N-dimethylbenzylamine as an acid-binding agent, first reacts 6-hydroxy-8-chlorooctanoic acid ethyl ester with a chlorination reagent in an organic solvent, and controls the reaction temperature, heats it after the reaction, and Control the heat preservation temperature and control the heat preservation time to obtain the reaction solution, add water to the layer, the upper layer is the organic phase, and rectify under reduced pressure to obtain 6,8-dichlorooctanoic acid ethyl ester, the lower layer is added with alkali to adjust the pH layer, and the upper layer is separated by Yuanming The powder is dehydrated to obtain N,N-dimethylbenzylamine for reuse. The chlorination ability is improved, the yield reaches about 95%, recycling is realized, waste water discharge is reduced, the process route is advanced, the process conditions are reasonable, the operation is simple and safe, the reaction yield is high, the production cost is low, and the three wastes are small.

Description

technical field [0001] The invention belongs to the technical field of preparation of organic compound intermediates, and in particular relates to a preparation method of ethyl 6,8-dichlorooctanoate. Background technique [0002] The English name of 6,8-dichlorooctanoic acid ethyl ester is: Ethyl6,8-dichlorocaprylate, the molecular formula is: C10H18Cl2O2, the molecular weight is: 241.15, and its chemical structure is as follows: [0003] [0004] 6,8-Dichlorooctanoic acid ethyl ester is an important organic intermediate for the synthesis of lipoic acid, and lipoic acid is called "universal antioxidant" and is widely used in the treatment and prevention of heart disease, diabetes and Alzheimer's disease, etc. diseases, the domestic and international markets have broad prospects. [0005] In the prior art, 6-hydroxy-8-chlorooctanoic acid ethyl ester is generally used as raw material to prepare 6,8-dichlorooctanoic acid ethyl ester. The specific preparation methods mainly ...

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Problems solved by technology

[0012] The task of the present invention is to use 6-hydroxyl-8-chlorooctanoic acid ethyl ester as raw material preparation method and the defective of existence of 6,8-dichlorooctanoic acid ethyl ester in the prior art, especially with 6-hydroxyl-8-chlorooctanoic acid ethyl ester Octanoic acid ethyl ester and thionyl chloride react under the condition of acid-binding agent with pyridine, the product yield is low, and the nitrogen-containing waste water that produces is many and with 6-hydroxyl-8-chlorooctanoic acid ethyl ester and chlorination reagent solid phosgene in N , N-dimethylformamide (DMF) is used as an acid-binding agent to carry out the chlorination reaction, and the water-containing DMF cannot be recovered, and the defects such as high cost do not meet the needs of modern industrial production and provide a 6-hydroxyl-8 -Ethyl chlorooctanoate reacts with chlorination reagents under the condition of N,N-dimethylbenzylamine as an acid-binding agent to obtain a high yield. The acid-binding agent can be recycled and reused after alkali treatment to reduce costs and waste water Discharge, to meet the needs of modern industrialized clean production of 6,8-dichlorooctanoic acid ethyl ester preparation method

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