New process for preparing hydroxy-acetic acid using hydroxy-acetic nitrile as raw material

A technology of hydroxyacetonitrile and glycolic acid, applied in nitrile preparation, organic chemistry, etc., can solve the problems of complex operation, low efficiency, complicated post-processing, etc., and achieve the effects of easy concentration, effective desalination, and convenient operation

Inactive Publication Date: 2007-04-11
重庆三峡英力化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The preparation of glycolic acid from hydroxyacetonitrile was previously completed by hydrolysis under strong acid or strong base. However, this method has been proved to be inefficient. In strong acid and strong base solutions, the generated products will polymerize, decompose, and even explode. US Patent US3,867,440 An improved scheme is disclosed, under the conditions of maleic acid, phosphorous acid and sulfurous acid, glycolic acid is hydrolyzed to prepare glycolic acid. The conversion rate of hydrolysis with maleic acid is

Method used

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  • New process for preparing hydroxy-acetic acid using hydroxy-acetic nitrile as raw material

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Hydroxyacetonitrile 100ml (379g / l), phosphoric acid 84.33g (85%), molar ratio 1: 1.1 in the 500ml four-neck flask at 112 ℃ reflux reaction 17 hours, the conversion rate of hydroxyacetonitrile reaches 99.32%, after concentrated crystallization desalination, The mother liquor was further desalted with 70 ml of acetone, and 27.1 g of glycolic acid with a content of 99.17% was obtained after post-treatment.

Embodiment 2

[0024] Hydroxyacetonitrile 100ml (392.32g / l), phosphoric acid 188.86g (84.5%), molar ratio 1: 2.8 in a 500ml four-neck flask at 90 ° C reflux reaction for 18 hours, the conversion rate of hydroxyacetonitrile reached 99.57%, after concentrated crystallization and desalination , the mother liquor was further desalted with 100ml of acetone, and after post-treatment, 29.3g of glycolic acid was obtained, with a content of 99.23%.

Embodiment 3

[0026] Hydroxyacetonitrile 250ml (410.4g / l), phosphoric acid 435.81g (83.85%), molar ratio 1: 2.1 in a 1000ml four-neck flask at 121 ° C reflux reaction for 16 hours, the conversion rate of hydroxyacetonitrile reached 99.34%, after concentrated crystallization and desalination , the mother liquor was further desalted with 240ml of acetone, and after post-treatment, 62.5g of glycolic acid was obtained, with a content of 98.79%.

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Abstract

The present invention provides process of preparing hydroxyacetic acid with hydroxyacetonitrile. The process includes the following steps; 1. adding proper amount of phosphoric acid into water solution of hydroxyacetonitrile and heating to hydrolyze; 2. concentrating crystallization to eliminate great amount of salt and further desalting with acetone; and 3. vacuum concentrating the acetone water solution to obtain the product hydroxyacetic acid.

Description

technical field [0001] The invention relates to a method for preparing glycolic acid from hydroxyacetonitrile. Background technique [0002] Glycolic acid is a very good cleaning agent. In European and American countries, it is a mandatory cleaning agent raw material for power plant boilers. It is a chemical intermediate with very good uses in the medical and cosmetic fields. The preparation of glycolic acid from hydroxyacetonitrile was previously completed by hydrolysis under strong acid or strong base. However, this method has been proved to be inefficient. In strong acid and strong base solutions, the generated products will polymerize, decompose, and even explode. US Patent US3,867,440 An improved scheme is disclosed, under the conditions of maleic acid, phosphorous acid and sulfurous acid, glycolic acid is hydrolyzed to prepare glycolic acid. The conversion rate of hydrolysis with maleic acid is not high, only 30%-70%, and with phosphorous acid and sulfurous acid Hydro...

Claims

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Application Information

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IPC IPC(8): C07C59/06C07C51/08
Inventor 雷洪陈小平郑长春冯倩
Owner 重庆三峡英力化工有限公司
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