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

A technology of dithiane and dihydroxy, which is applied in the field of preparation of 2,5-dihydroxy-1,4-dithiane, can solve the problems of long operation time, low content, poor washing effect, etc., and achieves short time , the effect of shortening the operation time

Active Publication Date: 2019-04-12
WEIFANG HUITAO CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

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

Method used

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

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Embodiment 1

[0027] Embodiment 1 A kind of preparation method of 2,5-dihydroxyl-1,4-dithiane

[0028] Include the following steps:

[0029] (1) Adjust the pH of chloroacetaldehyde

[0030] Weigh 1300kg of chloroacetaldehyde aqueous solution A, slowly add sodium bicarbonate to adjust the pH to 3.5, the solution color is colorless or light yellow and transparent, and obtain chloroacetaldehyde aqueous solution B.

[0031] The chloroacetaldehyde aqueous solution A has a mass content of 9-10% of chloroacetaldehyde and a mass content of 9-10% of free acid, and is colorless or light yellow and transparent.

[0032] (2) Preparation of sodium hydrosulfide solution

[0033] Prepare sodium hydrosulfide solution, the mass concentration is 32%, yellow-green transparent, and the total amount is 360kg.

[0034] (3) Add part of sodium hydrosulfide solution dropwise

[0035] Weigh 200.0kg of water into the reaction kettle, add 12kg of sodium hydrosulfide solution dropwise, start stirring, and cool down...

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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...

Claims

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Application Information

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IPC IPC(8): C07D339/08
CPCC07D339/08
Inventor 刘剑伟张全升韦兰星花现
Owner WEIFANG HUITAO CHEM
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