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Method for removing residues out of dimethyl sulfate

A technology for dimethyl sulfate and residues, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problem of poor removal effect, ester quaternary ammonium salt odor, and ineffective improvement of dimethyl sulfate Purity and other issues

Active Publication Date: 2014-02-12
HUBEI YUANDA FUCHI PHARMA CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The patent whose authorization notification number is CN101142171B discloses a method for removing residual sulfur dioxide from dimethyl sulfate, and the method adopts the method of adding an oxidizing agent in dimethyl sulfate to remove SO 2 , this method can only effectively remove sulfur dioxide residues in dimethyl sulfate, but it is not effective in removing residues such as dimethyl sulfite, and dimethyl sulfite will also cause odor of esterquat ammonium salts
In addition, this treatment method cannot effectively improve the purity of dimethyl sulfate, and does not involve the removal of oxidant after the reaction, especially when hydrogen peroxide is used as the oxidant, the introduced water will exist in dimethyl sulfate for a long time, which will lead to disulfide Hydrolysis of methyl esters, turbidity, reducing the content of dimethyl sulfate and increasing its acidity

Method used

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  • Method for removing residues out of dimethyl sulfate

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Effect test

Embodiment 1

[0028] Weigh the acidity as 0.32%, SO 2 The content is 207ppm, (CH 3 O) 2 SO content is the dimethyl sulfate 400g of 462ppm in the 500ml there-necked flask with stirring, then add the H of 0.9g mass concentration 30% 2 o 2 . Start stirring, and then put 0.4g of MnO into the system 2 , heating up, when the system temperature rises to 35 0 Start timing at C, and at this temperature (35±2 0 C) Insulation reaction for 3.5h. End the reaction, and add 10g molecular sieve to the system, let stand for 36h, filter out molecular sieve and MnO 2 , the obtained dimethyl sulfate has an acidity of 0.25%, SO 2 8.9ppm, (CH 3 O) 2 SO 18.7ppm, the product appearance is colorless, clear and transparent.

Embodiment 2

[0030] Weigh the acidity as 0.32%, SO 2 The content is 207ppm, (CH 3 O) 2 SO content is the dimethyl sulfate 400g of 462ppm in the 500ml there-necked flask with stirring, then add the H of 0.5g mass concentration 50% 2 o 2 . Start stirring, and then put 0.4g of MnO into the system 2 , heating up, when the system temperature rises to 35 0 Start timing at C, and at this temperature (35±2 0 C) Insulation reaction for 3.5h. Finish the reaction, and add 6g of silica gel to the system, let stand for 40h, filter out silica gel and MnO 2 , the acidity of the obtained dimethyl sulfate is 0.24%, SO 2 9.8ppm, (CH 3 O)2 SO 20.6ppm, the product appearance is colorless, clear and transparent.

Embodiment 3

[0032] Weigh the acidity as 0.32%, SO 2 The content is 207ppm, (CH 3 O) 2 SO content is the dimethyl sulfate 400g of 462ppm in the 500ml there-necked flask with stirring, then add the H of 0.9g mass concentration 30% 2 o 2 , start stirring. Drop into the CaO of 0.35g in the system again, heat up, when the system temperature rises to 48 0 Start timing at C, and at this temperature (48±2 0 C) Insulation reaction for 4.0h. Finish reaction, and add 10g calcium chloride in the system, filter out calcium chloride and CaO after leaving standstill 38h, gained dimethyl sulfate acidity 0.22%, SO 2 11.5ppm, (CH 3 O) 2 SO 17.9ppm, the product appearance is colorless, clear and transparent.

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Abstract

The embodiment of the invention provides a method for removing residues out of dimethyl sulfate, belonging to the technical field of chemical purification. The method comprises the steps: adding a catalyst and a hydrogen peroxide solution with the mass concentration of 30-70%, reacting at the temperature of 35-55 DEG C, removing residues, and separating the catalyst and water to obtain high-purity dimethyl sulfate after the reaction is finished, wherein the usage amount of the hydrogen peroxide solution is 0.15-0.35% of that of the dimethyl sulfate, the usage amount of the catalyst is 0.05-0.2% of weight of the dimethyl sulfate, and the catalyst comprises manganese dioxide, calcium oxide, cobalt sulfate or copper sulfate. The method for removing residues, provided by the invention, can be used for effectively removing the residues such as CHOSO3H, SO2 and (CH3O)2SO out of the dimethyl sulfate, and a treated dimethyl sulfate product contains more than or equal to 99.5% of DMS, less than or equal to 20ppm of SO2 and less than or equal to 30ppm of (CH3O)2SO, so that the removing effect is very remarkable.

Description

technical field [0001] The invention belongs to the technical field of chemical purification, in particular to a method for removing residues in dimethyl sulfate. Background technique [0002] Dimethyl sulfate, used in the manufacture of dyes and as a methylating agent for amines and alcohols. It can be used as reaction raw material, solvent, analysis reagent and methylation reagent. Its vapor is highly toxic and has been used as a war gas. Specifically, it can be used as a reagent for the determination of coal tars, and as a methyl substitution agent in organic synthesis. [0003] The dimethyl sulfate produced by prior art contains a small amount of CHOSO 3 H, SO 2 , (CH 3 O) 2 SO and other residues. The existence of residues will affect the use of dimethyl sulfate. For example, when preparing esterquats, at higher temperatures, some by-products are formed, which negatively affects the odor of dimethyl sulfate quaternization products. impact, these odor-related prob...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C305/08C07C303/44
Inventor 雷大有熊先胜江灿
Owner HUBEI YUANDA FUCHI PHARMA CHEM
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