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Method for preparing 4-hydroxyphenyl hydantoin

A technology of p-hydroxybenzohydantoin and ureidobenzene, which is applied in the field of medicine and chemical industry, can solve the problems of waste of raw materials and energy, increased production waste liquid treatment cost and environmental pollution pressure, low production yield and the like, and achieves product quality and synthesis. The effect of improving yield, improving utilization rate and reducing production cost

Inactive Publication Date: 2011-02-16
TIANJIN VOCATIONAL INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] my country has become the main producer of p-hydroxyphenylhydantoin in the world. With the continuous expansion of production scale, the low production yield not only causes a lot of waste of raw materials and energy, but also increases the cost of production waste liquid treatment and the pressure of environmental pollution. It is urgent to improve Production technology, seeking an effective way for clean production and energy saving of p-hydroxyphenylhydantoin

Method used

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  • Method for preparing 4-hydroxyphenyl hydantoin
  • Method for preparing 4-hydroxyphenyl hydantoin

Examples

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Effect test

Embodiment 1

[0023] Add urea 36g (0.6mol), phenol 40g (0.42mol), sulfamic acid 19.4g (0.10mol), deionized water 200mL and 100mL of 30% hydrochloric acid, start stirring, when the temperature of the feed liquid rises to 50-60°C, start to add 74.0g (0.4mol) of 40% glyoxylic acid solution dropwise, and the dropwise addition is completed in 8-10 hours, then keep warm at 80°C for 4 Hours, the reaction was incubated at 105°C for 2 hours. Then cool to 35°C, vacuum filter the precipitated white p-hydroxyphenylhydantoin crystals, wash with hot water at 40-50°C until the crystals are not easy to stick, soak in methanol, and weigh 48.4g after drying. The content is 99.6% as determined by liquid chromatography. The yield of p-hydroxyphenylhydantoin was 62.7%.

[0024] The mother liquor is neutralized to PH4-6 with concentrated ammonia water, and precipitates containing p-hydroxyphenylglycine, p-hydroxyphenylhydantoin and by-products are precipitated, the solution is cooled to 10-15°C to complete the ...

Embodiment 2

[0026]Add urea 36g (0.6mol), phenol 40g (0.42mol), sulfamic acid 19.4g (0.20mol), deionized water 200mL and 100mL of 30% hydrochloric acid, start stirring, when the temperature of the feed liquid rises to 50-60°C, start to add 74.0g (0.4mol) of 40% glyoxylic acid solution dropwise, the dropwise addition is completed in 8-10 hours, and then keep warm at 80°C for 4 Hours, the reaction was incubated at 105°C for 2 hours. Then cool the reaction liquid to 35°C, vacuum filter the precipitated white p-hydroxyphenylhydantoin crystals, wash with hot water at 40-50°C until the crystals are not easy to stick, soak in methanol, and weigh 44.4g after drying, and determine the content by liquid chromatography 99.5%, and the yield of p-hydroxyphenylhydantoin is 57.5%.

[0027] The mother liquor is neutralized to PH4-6 with concentrated ammonia water, and precipitates containing p-hydroxyphenylglycine, p-hydroxyphenylhydantoin and by-products are precipitated, the solution is cooled to 10-15...

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Abstract

The invention discloses a method for preparing 4-hydroxyphenyl hydantoin from a glyoxylic acid, phenol and urea by condensation under acid condition, which is characterized in that: the 4-hydroxyphenyl hydantoin is prepared in the presence of a sulfamic acid, the production of polymerization impurities is inhibited and simultaneously a phenylglycine byproduct is produced. The mol ratio of the reaction raw materials of the glyoxylic acid to the phenol to the urea to the sulfamic acid is 1:1.0-1.1:1-1.5:0.2-0.5. The method comprises the following steps of: adding dropwise glyoxylic acid solution at the relatively lower temperature of 50 to 60 DEG C to form a 2-ureidobenzeneacetic acid intermediate, preparing the 4-hydroxyphenyl hydantoin at the relatively higher temperature of 80 or 105 DEG C by ring formation and simultaneously producing the p-hydroxyphenylglycine byproduct, wherein reaction solution is subjected to post-treatment to obtain white 4-hydroxyphenyl hydantoin crystals with the purity of 99.6 percent and the yield of 62.7 percent; and mother solution is further treated to obtain white p-hydroxyphenylglycine crystals with the purity of 99.2 percent ad the yield of 10.1 percent. In the method, the main byproduct is p-hydroxyphenylglycine, the utilization rate of the synthesis raw materials is increased and the problems of unstable quality of product and high treatment cost of the mother solution in the prior art are solved.

Description

technical field [0001] The invention relates to a method for preparing p-hydroxyphenylhydantoin by condensation of glyoxylic acid, phenol and urea under acidic conditions, especially preparing p-hydroxyphenylhydantoin in the presence of sulfamic acid, which can inhibit the formation of polymeric impurities and simultaneously generate p-hydroxyphenylhydantoin The method for the by-product of hydroxyphenylglycine belongs to the field of medicine and chemical industry. Background technique [0002] 4-Hydroxyphenyl hydantoin (English name 4-Hydroxyphenyl hydantoin), molecular formula C 9 h a N 2 o 3 , molecular weight 192.2, melting point greater than 260 ° C, insoluble in water and alcohol solvents. P-Hydroxydiphenylhydantoin is an important raw material for the production of lactam antibiotics such as amoxicillin and amoxicillin cephalosporin. P-hydroxyphenylhydantoin is industrially produced by the condensation reaction of glyoxylic acid, phenol and urea under strongly a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/36C07D233/78C07C227/18
Inventor 李建生
Owner TIANJIN VOCATIONAL INST
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