Chemical method for synthesizing 6,8-dichloro ethyl cacodylic acid caprylate

Abstract

The invention discloses a chemical synthetic method for 6, 8-ethyl octylate chloride. The method comprises the steps as follows that: 6-hydroxyl-8-ethyl octylate chloride is dissolved in N, N-dimethylformamide; solution which is dissolved with organic solution of double (trichloride trichloromethyl)-carbonic acid ester is dropped in when in mixing under cold water bath condition; the solution is gradually warmed to 50 to 90 DEG C for reacting for 2 to 8 hours after dropping; and the reaction solution is disposed into 6, 8-ethyl octylate chloride after finishing the reaction. As the invention replaces sulphoxides chloride with double (trichloride trichloromethyl)-carbonic acid ester, the invention produces environment friendly Vilsmeier agent which needs not to be separated in the reaction, and the Vilsmeier agent directly reacts with 6-hydroxyl-8-ethyl octylate chloride to produce 6, 8-ethyl octylate chloride. Besides, the invention has the advantages of advanced technique, rational technological condition, simple and safe operation, high reaction yield, low production cost, low three-waste emission and great implementation value and social and economic efficiency.

Description

(1) Technical field [0001] The present invention relates to a kind of chemical synthesis method of 6,8-dichlorooctanoic acid ethyl ester, particularly relate to using bis(trichloromethyl)carbonate and 6-hydroxy-8-chlorooctanoic acid ethyl ester and N,N-dimethyl A chemical synthesis method for preparing 6,8-dichlorooctanoic acid ethyl ester by formamide reaction. (2) Background technology [0002] 6,8-Dichlorooctanoic acid ethyl ester is an important organic intermediate for the synthesis of lipoic acid. Lipoic acid is known as "universal antioxidant" and is widely used in the treatment and prevention of various diseases such as heart disease, diabetes, and Alzheimer's disease, and has broad domestic and international market prospects. [0003] Before the present invention was given, the chemical synthesis method of ethyl 6,8-dichlorooctanoate in the prior art was mostly prepared by chlorination of ethyl 6-hydroxy-8-chlorooctanoate and thionyl chloride. As reported in liter...

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Problems solved by technology

As reported in literature [Zhuranl Obshchei Khimii, 1964,34,3662], the 6-hydroxyl-8-chlorooctanoic acid ethyl ester and thionyl chloride were refluxed in benzene for 1h in the presence of a catalytic amount of pyridine to generate 6,8 -Ethyl dichlorooctanoate (crude product yield 88%), contain a large amount of asphyxiating sulfur dioxide (one of six indicators that national environmental protection strictly controls atmosphere) in this process tail gas, handle difficulty, mainly adopt alkali absorption to prepare sodium sulfite and sodium sulfite at present A mixture of sodium chloride, but there is a big problem in the market, and, because it is an aqueous solution after being absorbed by alkali, it must be concentrated to obtain a mixture of sodium sulfite and sodium chloride, the production process consumes a lot of energy, and the production cost is relatively high

In addition, the transportation and use of thionyl chloride are strictly controlled, and the requirements for the sealing of the reaction equipment are high, and the investment is also relatively large. At the same time, the catalyst pyridine smells bad in the original process, and the operating environment is very bad. The reaction solvent benzene has been strictly restricted in my country. Problems such as use, low product yield and purity need to be solved

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