Preparation method of glycine

A technology of glycine and chloroacetic acid, which is applied in the field of chemical production, can solve the problems of yield and purity decline, cost increase, environmental pollution, etc., and achieve the effects of simple preparation method, production cost saving and environmental friendliness

Pending Publication Date: 2021-07-30
HEBEI DONGHUA JIHENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method has many disadvantages. The yield of glycine is only about 85%. The production of one ton of glycine requires rectification of about 13 cubic meters of methanol solution, which requires high energy and equipment consumption. At the same time, the production of one ton of glycine requires 150 kilograms of urethane Tropin cannot be recycled, and ammonium chloride needs to be obtained by evaporating and concentrating solvent water, which consumes a lot of energy, and the final red wastewater needs to be further treated, otherwise it will cause great pollution to the environment
[0004] Patent CN1080632A proposes an improved synthesis method of glycine, using chloroacetic acid and ammonia as raw materials, using organic amines such as triethylamine, tripropylamine and tributylamine as acid-binding agents to obtain glycine with higher purity, but catalysts and organic amines have no be effectively reused
[0005] In patent CN102030669A, in the presence of a catalyst, chloroacetic acid and ammonia are used as raw materials, and organic amines are used as acidic agents to separate glycine and ammonium chloride. However, ammonia is passed through the mother liquor after separating glycine to obtain ammonium chloride. Difficult to control, unable to fully recover triethylamine, and easy to obtain mixed crystals of glycine and ammonium chloride, need further treatment
What reclaimed is the methanol mother liquor of triethylamine, if the reactant is chloroacetic acid during recycling, triethylamine and chloroacetic acid react to generate by-products, yield and purity decline; if the reactant is ammonium chloroacetate, it needs to be processed to obtain Ammonium chloroacetate or buy, add cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Add 192g of chloroacetic acid (content 98%) and 800g of methanol into a four-neck bottle, put in a magnet, install a thermometer and a reflux condenser, and after the chloroacetic acid is stirred and dissolved, start to pass ammonia, and control the temperature of ammonia flow at 10-30°C , Stop passing ammonia after the solution reaches alkaline pH=9. Add 72g of urotropine, raise the temperature to 66°C, start adding 204g of triethylamine dropwise, keep the temperature at 65-70°C, complete the dropwise addition within 1 hour, and keep warm for 0.5h after dropping. Cool down to 20-30°C, filter, rinse the filter cake with 92% methanol, filter, and dry to obtain 149.1 g of glycine with a purity of 97.8% and a molar yield of glycine based on chloroacetic acid of 97.6%. The filtered reaction solution was evaporated and concentrated at a temperature of 50°C and a vacuum pressure of -0.085MPa--0.095MPa. After 300mL of methanol was distilled off, the remaining mother liquor was...

Embodiment 2

[0028] Add 50g of chloroacetic acid (content 98%) and 200g of methanol evaporated in Example 1 into the beaker, after stirring and dissolving the chloroacetic acid, start passing ammonia, control the temperature of passing ammonia at 10-30°C, and make the solution reach alkaline pH=9 Then stop the ammonia. Add the reaction mother liquor that contains urotropine in the solution that has reacted and embodiment one in the four-neck bottle, the volume of the reaction mother liquor that contains urotropine among the described embodiment one is the volume of the reaction mother liquor that contains urotropine that implements one obtains 26% of the total volume of the reaction mother liquor, install a thermometer and a reflux condenser, raise the temperature to 66°C, start adding 52g of triethylamine dropwise, maintain the temperature at 65-70°C, complete the dropwise addition within 1h, and keep warm for 0.5h after dropping. Cool down to 20-30°C, filter, rinse the filter cake with 9...

Embodiment 3

[0031] Add 50g of chloroacetic acid (content 98%) and 200g of methanol evaporated in Example 2 into the beaker. After the chloroacetic acid is stirred and dissolved, start passing ammonia, and control the temperature of passing ammonia at 10-30°C, and the solution reaches alkaline pH=9 Then stop the ammonia. Add the reacted solution and the reaction mother liquor containing urotropine in Example 2 into a four-necked bottle, install a thermometer and a reflux condenser, raise the temperature to 66°C, start adding 52g of triethylamine dropwise, and maintain the temperature at 65- 70°C, the dropwise addition is completed within 1 hour, and the dropwise temperature is kept for 0.5 hour. Cool down to 20-30°C, filter, rinse the filter cake with 92% methanol, filter, and dry to obtain 38.8 g of glycine, with a purity of 98.0%, and a molar yield of glycine based on chloroacetic acid of 97.6%. The filtered reaction solution was evaporated and concentrated at a temperature of 50°C and ...

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PUM

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Abstract

The invention relates to a preparation method of glycine, which belongs to the technical field of chemical production and comprises the following five steps: preparing an ammonium chloroacetate solution, preparing a product glycine solution, preparing a glycine finished product, recovering to obtain an organic amine hydrochloride crystal solid and a filtrate containing urotropine, recovering an organic amine solution and preparing an ammonium chloride solid. The preparation method disclosed by the invention is simple and environment-friendly, the prepared glycine product is high in purity, and meanwhile, an industrial-grade ammonia chloride product can be obtained through co-production; the organic amine, the methanol and the catalyst urotropine used in the preparation process can be recycled, so that the production cost is saved, and the purpose of zero emission is achieved.

Description

technical field [0001] The invention relates to a preparation method of glycine, which belongs to the technical field of chemical production. Background technique [0002] Glycine, also known as aminoacetic acid, is a non-essential amino acid. As an important fine chemical product, amino acid has important uses in food, medicine, agriculture, industry, etc. In terms of food, glycine can be used as a nutritional supplement, as a flavoring agent, and can also play a seasoning role. At the same time, it has a certain inhibitory effect on the reproduction of Bacillus subtilis and Escherichia coli; Combination with aspirin can reduce the irritation to the stomach, and can also treat hyperprolinemia in children; in agriculture, glycine is an intermediate of synthetic pyrethroid insecticides, glycine ethyl ester hydrochloride, synthetic pyrethroids It is an important raw material for the fungicide iprodione and the herbicide solid glyphosate, and can also be used as an additive an...

Claims

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Application Information

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IPC IPC(8): C07C227/08C07C227/42C07C229/08C07C51/41C07C53/16
CPCC07C227/08C07C227/42C07C51/412C07C53/16C07C229/08
Inventor 宋铁犇代景茹宋同旺卢淑婷赵静翟学昌赵亚伟张敬思李顺双曾著飞曹甲宁曲艳敏赫旭欢吴华岳张鑫
Owner HEBEI DONGHUA JIHENG CHEM
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