Preparation method of ethyl 6,8-dichlorocaprylate

Abstract

The invention relates to a preparation method of ethyl 6,8-dichlorocaprylate, belonging to the technical field of preparation of organic compound intermediates. The preparation method comprises the steps of reacting ethyl 6-hydroxy-8-chlorocaprylate with a chlorination agent in an organic solvent by taking N,N-dimethylbenzylamine as an acid-binding agent, controlling the reaction temperature, maintaining the temperature after the reaction is finished, and controlling the temperature maintaining temperature and the temperature maintaining time to obtain reaction liquid, adding water for layering to obtain an organic phase at an upper layer, carrying out reduced pressure rectification to obtain ethyl 6,8-dichlorocaprylate, adding alkali to a lower layer to regulate pH for layering, and carrying out dehydration on the upper layer by virtue of anhydrous sodium sulphate so as to obtain N,N-dimethylbenzylamine, and recycling. By virtue of the preparation method, the chlorination capacity is improved, the yield reaches about 95%, the cycle use is realized, the discharging of wastewater 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 relatively low, and three wastes are little.

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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