Preparation process for cyanomethyl ester

A cyanomethyl ester and preparation technology, which is applied in the field of cyanomethyl ester preparation technology, can solve the problems of product yield reduction, hydrochloride is prone to side reactions, etc., and achieve the effect of smooth reaction process

Inactive Publication Date: 2015-10-21
NANTONG TENDENCI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] In the second step of ester formation reaction, 28% aqueous solution of cyanamide is used. At this time, ethyleneimine methyl ether hydrochloride is very prone to side reactions, resulting in product Yield reduces, therefore, improving processing condition, high yield is the object of the present invention to prepare cyanomethyl ester

Method used

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  • Preparation process for cyanomethyl ester
  • Preparation process for cyanomethyl ester

Examples

Experimental program
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Embodiment 1

[0023] Example 1: Add 287Kg (7Kmol) of acetonitrile, 224Kg (7Kmol) of methanol, and 520Kg of solvent toluene to a 3000L synthesis reactor, start stirring and freezing brine, and cool the materials in the reactor to 0-5°C. At the above temperature, start to feed 268.5Kg (7.36Kmol) of hydrogen chloride gas, usually about 10 hours. After the ventilation is over, the material in the reactor is gradually raised to 25-30°C, and the salt-forming reaction is started for 7 hours, and the salt-forming reaction is completed.

[0024] Under stirring, cool the reaction solution to 0°C, slowly add 50Kg of ammonium carbonate, and then add 1050Kg (7Kmol) of 28% cyanamide aqueous solution, and adjust the pH value to 6.0-6.5 with 30% aqueous sodium hydroxide solution. -20 ℃ heat preservation reaction for 1 hour, the ester-forming reaction is completed.

[0025] After standing still for half an hour, the organic layer was separated and recovered, and the organic layer was vacuum distilled to ob...

Embodiment 2

[0026] Example 2: Add 287Kg (7Kmol) of acetonitrile, 224Kg (7Kmol) of methanol, and 574Kg of solvent toluene to a 3000L synthesis reactor, start stirring and freezing brine, and cool the materials in the reactor to 0-5°C. At the above temperature, start to feed 270Kg (7.40Kmol) of hydrogen chloride gas, usually about 9 hours. After the aeration, the material in the reactor is gradually raised to 25-30°C, and the salt-forming reaction is started for 6 hours, and the salt-forming reaction is completed.

[0027] Under stirring, cool the reaction solution to 0°C, slowly add 50Kg of ammonium carbonate, and then add 1050Kg (7Kmol) of 28% cyanamide aqueous solution, and adjust the pH value to 6.0-6.5 with 30% aqueous sodium hydroxide solution. -20 ℃ heat preservation reaction for 1 hour, the ester-forming reaction is completed.

[0028] After standing still for half an hour, the organic layer was separated and recovered, and the organic layer was vacuum distilled to obtain the produ...

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Abstract

The invention relates to the chemical field and in particular to a preparation process for cyanomethyl ester. The cyanomethyl ester is prepared with a high yield by taking acetonitrile, methanol, anhydrous hydrogen chloride and a 28% cyanamide aqueous solution as main reaction raw materials and taking toluene as a solvent. The preparation process has the advantage that according to the preparation method for the cyanomethyl ester, the molar yield of the cyanomethyl ester is increased to 85%; content of product cyanomethyl ester is greater than or equal to 99.5%; and the reaction process is gentle and safe.

Description

Technical field: [0001] The invention relates to the field of chemical industry, in particular to a preparation process of cyanomethyl ester. Background technique [0002] Cyanoethyl ester is an important intermediate used in the synthesis of the pesticide acetamiprid. Cyanoethyl ester is prepared by the reaction of acetonitrile, methanol, hydrogen chloride and cyanamide. The reaction principle is: [0003] [0004] Acetonitrile Methanol Hydrogen Chloride Ethimine Hydrochloride [0005] [0006] Cyanamide Cyanomethyl ester [0007] It can be seen from the above reaction principle that the reaction is carried out in two steps. The first step of salt formation reaction is carried out under anhydrous conditions in the presence of toluene solvent, and the high yield obtains ethyleneimine methyl ether hydrochloride, and then in the first step reaction solution Add 28% cyanamide aqueous solution to carry out ester-forming reaction, adjust the pH value during the reacti...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C257/08
Inventor 谭建平周甦金标朱晓一
Owner NANTONG TENDENCI CHEM
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