Production method of 3-chloropropionic acid

Abstract

The invention discloses a production method of 3-chloropropionic acid. The method comprises the following steps of 1, continuous reactor assembly; 2, 3-chloropropionic acid preparation; 3, 3-chloropropionic acid purification; 4, 3-chloropropionic acid continuous production. The production method has the advantages that the method is simple; the operation is convenient; the acrylic acid conversionrate is high; the 3-chloropropionic acid with the purity being higher than 99 percent can be obtained without purification; the energy consumption is low.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a production method of 3-chloropropionic acid. Background technique [0002] 3-Chloropropionic acid is a chemical raw material used in organic synthesis. It is mainly used in medicine, pesticides, etc. It can also be used to produce 3-mercaptopropionic acid, which is used in commercial concrete water reducers and as polymerization terminators. [0003] Regarding the synthesis of 3-chloropropionic acid, it was prepared by using propionolactone and chloride, hydrochloric acid or sulfuric acid in the early stage, see US2449987, GB635348; there is also the use of propionic acid chlorination to prepare 3-chloropropionic acid, see CN1349969. At present, acrylic acid and hydrochloric acid or hydrogen chloride are mainly used to produce 3-chloropropionic acid, see EP729935, US20120190879, CN1138569, SU1816756, CN1569799. As the price of acrylic acid drops, this rout...

AI Technical Summary

Problems solved by technology

There are few patents for the synthesis of 3-chloropropionic acid by heating and hydrolyzing acrylonitrile and hydrogen chloride, see JP5821640, JP582164, because acrylonitrile itself is relatively expensive, and it is not economical to use it to synthesize 3-chloropropionic acid

[0004] The above four methods have all been used in the industrial production of 3-chloropropionic acid, but currently only the acrylic acid method is the most promising, so there are many reported patents, but these patented methods have limitations, because the addition of acrylic acid and hydrogen chloride is a long process , no matter what the temperature and pressure are, it will take a long time to complete the reaction, and in order to achieve complete reaction, it is not easy to achieve high purity without fractionation, and fractionation purification will lose yield, because 3-chloropropionic acid is Temperature sensitive, easy to dehydrochloride and return to acrylic acid, and the decomposition of hydrogen chloride will corrode the equipment