A kind of method for preparing mono-l-menthyl glutarate

A technology of glutaric acid mono-menthyl ester, which is applied in the preparation of carboxylic acid esters, chemical instruments and methods, and the preparation of organic compounds. It can solve the problems of low conversion rate, waste of raw materials, and many by-products, and achieve high yield Effect

Inactive Publication Date: 2016-06-22
HENAN ACADEMY OF SCI CHEM RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The preparation of glutaric acid mono-L-menthyl by glutaric anhydride and menthol adopts solvent reaction, and the conversion rate is low; adopts solvent-free reaction, and menthol is easy to sublimate, resulting in waste of raw materials
[0004] Domestically, there are relevant literature research reports on the direct synthesis of glutaric acid mono-L-menthol with glutaric anhydride and menthol as raw materials, and the yield is mostly 70% to 80% (see Chen Yu et al., Henan Chemical Industry 2014, 31(4) ; Huo Cuimeng et al., Henan Science 2013, 31(10)), all of them use solvent reaction, there are many by-products, and it is difficult to fully utilize the raw materials

Method used

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  • A kind of method for preparing mono-l-menthyl glutarate

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Effect test

Embodiment 1

[0015] Add glutaric anhydride 13.7g, menthol 15.6g artificial zeolite (Na 2 O·Al 2 o 3 · xSiO 2 ·yH 2 O) 3.2g, toluene 30ml. Gradually raise the temperature to 90°C, remove toluene by distillation under reduced pressure, react at 120°C for 4 hours, add 50ml of toluene after the reaction, add 200g of 5% sodium carbonate solution by mass, stir and separate layers, add 3N hydrochloric acid to the water layer, and adjust the pH value to 3 , stirred, extracted with ethyl acetate, dried the organic layer, filtered and distilled off the solvent under pressure, and dried to obtain 24.6g of glutaric acid mono-L-menthyl ester with a content of 98.7% and a menthol conversion rate of 91%.

Embodiment 2

[0017] Add glutaric anhydride 13.7g, menthol 15.6g artificial zeolite (BaO Al 2 o 3 · xSiO 2 ·yH 2 O) 3.2g, chloroform 25ml. Gradually raise the temperature to 90°C, remove chloroform by distillation under reduced pressure, react at 130°C for 5 hours, add 35ml of chloroform after the reaction, add 200g of 5% sodium carbonate solution by mass, stir and separate layers, add 3N hydrochloric acid to the water layer, and adjust the pH value to 3 , stirred, extracted with ethyl acetate, dried the organic layer, filtered and distilled off the solvent under pressure, and dried to obtain 24.1 g of mono-L-menthyl glutarate, with a content of 98.5% and a conversion rate of menthol of 89%.

Embodiment 3

[0019] Add glutaric anhydride 13.7g, menthol 15.6g artificial zeolite (K 2 O·Al 2 o 3 · xSiO 2 ·yH 2 O) 3.2g, butyl ether 40ml. Gradually raise the temperature to 90°C, remove butyl ether by distillation under reduced pressure, react at 90°C for 3.5 hours, add 55ml of butyl ether after the reaction, add 200g of 5% sodium carbonate solution by mass, stir and separate layers, add 3N hydrochloric acid to the water layer, and adjust the pH value 1, stirred, extracted with ethyl acetate, dried the organic layer, filtered and distilled off the solvent under pressure, and dried to obtain 23.5 g of mono-L-menthyl glutarate with a content of 98.7% and a conversion rate of menthol of 87%.

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Abstract

The invention discloses a feeding manner for preparing L-monomenthyl glutarate with glutaric anhydride and menthol and belongs to the field of organic chemical synthesis. According to the method takes the glutaric anhydride and the menthol as the raw materials and artificial zeolite as the catalyst and comprises adding in solvent for dissolution, and after the temperature rises, reducing temperature and removing the solvent to achieve solvent-less reaction and further to obtain the L-monomenthyl glutarate. The feeding manner for preparing the L-monomenthyl glutarate mainly solves the problem that, during the process of preparing the L-monomenthyl glutarate through solvent-less reaction, the menthol can easily sublimate to result in low conversion ratio, so that the material cost for preparing the L-monomenthyl glutarate can be reduced, the shortcoming of high viscosity and stirring difficulty at the beginning of the solvent-less reaction can be avoided, subsequent processes can be facilitated, and a series of problems caused by sublimation of the menthol can be eliminated. The feeding manner for preparing the L-monomenthyl glutarate can improve the conversion rate of the menthol from originally 73% to more than 87%.

Description

technical field [0001] The invention relates to a method for preparing novel cooling agent L-menthyl glutarate from glutaric anhydride and menthol, which belongs to the field of organic chemical synthesis. Background technique [0002] Menthol cooling agent is an important organic raw material, which is used in medicine, food, tobacco, light industry and other fields. It has strong volatility and strong penetrating power. The high-concentration menthol vapor has a strong stimulating and eroding effect on human skin and mucous membranes. Combining menthol and organic acid produces a menthyl ester cooling agent, which is more stable than pure menthol due to its relatively high volatilization temperature. Therefore, the development of esters related to menthol is of great significance for expanding the application field of menthol. [0003] As a cooling agent, L-menthyl glutarate has been certified by the U.S. FDA. It is a new type of cooling agent approved by the U.S. Food a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C67/08C07C69/42
CPCC07C67/08C07C69/42
Inventor 代本才赵永德霍萃萌陈瑨张豫黎郭深深王兰天
Owner HENAN ACADEMY OF SCI CHEM RES INST CO LTD
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