Preparation method for 2,5-dihydroxyl-1,4-dithiane

Abstract

The invention provides a preparation method for 2,5-dihydroxyl-1,4-dithiane. The preparation method comprises the steps of adjusting pH of chloroacetaldehyde, preparing a sodium hydrosulfide solution,dropwise adding part of sodium hydrosulfide solution, carrying out a dropwise adding reaction, and carrying out aging. The 2,5-dihydroxyl-1,4-dithiane prepared by the method has a yield not lower than 90.0%; the appearance of the 2,5-dihydroxyl-1,4-dithiane prepared by the method is white-like or yellowish powder, and the content of dithiane is not lower than 97.0%; the moisture content is not higher than 0.5%; the clarity is of colorless transparent liquid (N,N-dimethylformamide serves as a solvent); and a melting range is 135.0 DEG C to 150.0 DEG C.

Description

technical field [0001] The invention provides a preparation method of 2,5-dihydroxy-1,4-dithiane, which belongs to the technical field of chemical synthesis. Background technique [0002] 2,5-dihydroxy-1,4-dithiane is an intermediate for the production of lamivudine and emtricitabine, the existing method for preparing 2,5-dihydroxy-1,4-dithiane, There are following deficiencies: [0003] (1) Low yield; [0004] (2) The preparation process of 2,5-dihydroxy-1,4-dithiane includes adjusting the pH of chloroacetaldehyde, preparing sodium hydrosulfide solution, adding part of sodium hydrosulfide solution dropwise, adding reaction, and aging steps. Finally, there are impurities such as by-product chlorides and unreacted sulfides in the product, and the washing effect is not good, resulting in low content of 2,5-dihydroxy-1,4-dithiane in the finished product; [0005] (3) The operation time is long. Contents of the invention [0006] In order to solve the above technical probl...

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Problems solved by technology

[0003] (1) Low yield;

[0004] (2) The preparation process of 2,5-dihydroxy-1,4-dithiane includes adjusting the pH of chloroacetaldehyde, preparing sodium hydrosulfide solution, adding part of sodium hydrosulfide solution dropwise, adding reaction, and aging steps. Finally, there are impurities such as by-product chlorides and unreacted sulfides in the product, and the washing effect is not good, resulting in low content of 2,5-dihydroxy-1,4-dithiane in the finished product;

[0005] (3) Long operating time

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