Ester ammonolysis reaction catalyst composition and preparation method of L-menthane carboxamide

A technology of menthamide and catalyst is applied in the field of ester aminolysis reaction catalyst composition, and can solve the problems of severe reaction conditions, racemization, and difficulty in industrialization, and achieve the effects of ensuring optical purity, reducing raw material costs, and reducing environmental protection costs.

Active Publication Date: 2020-07-10
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

L-menthol has the advantages of strong coolness, low threshold and low price, but it also has some obvious disadvantages, such as strong pungent smell, bitter taste, no obvious cooling effect when the dosage is low, and there will be some when the concentration is large. Burning sensation, strong volatility, short action time, etc. These shortcomings limit the application of L-menthol in many fields to a certain extent, especially in chewing gum and some special types of cosmetics
However, there are two defects in this method: 1) the preparation of the raw material L-menthylcarbonitrile requires the use of highly toxic NaCN and the reaction conditions are severe, making it difficult to industrialize; The chiral center at the alpha position of the carbonyl group undergoes racemization

Method used

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  • Ester ammonolysis reaction catalyst composition and preparation method of L-menthane carboxamide
  • Ester ammonolysis reaction catalyst composition and preparation method of L-menthane carboxamide
  • Ester ammonolysis reaction catalyst composition and preparation method of L-menthane carboxamide

Examples

Experimental program
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Effect test

Embodiment 1

[0034] (1) Synthesis of L-Methyl Formate

[0035] At 20°C, under the protection of N2 gas, methyl chloroformate (14.1 g, 0.15 mol) was added dropwise to the above-mentioned menthyl magnesium chloride tetrahydrofuran solution for 1 h, and then kept stirring for 0.5 h after the addition was completed. Then filter to remove the MgCl generated by the reaction 2 solid, the resulting solution was directly subjected to the next reaction.

[0036] (2) Synthesis of L-menthol amide

[0037] At 25°C, add CuBr (0.02 g, 0.15 mmol) and the ligand to the menthyl formate tetrahydrofuran solution obtained in (1) (0.05g, 0.15mmol), followed by ethylamine (6.75g, 0.15mol) for 2h. After the reaction, the reaction solution was concentrated by rectification under reduced pressure at 35°C until a small amount of solids precipitated, then dropped to 0°C within 2 hours, filtered and dried to obtain the final product, L-menthylamide, calculated as menthyl chloride. Yield 95%. The product has a melt...

Embodiment 2

[0039] (1) Synthesis of L-menthyl ethyl formate

[0040] At 25°C, under the protection of N2 gas, add ethyl chloroformate (19.4 g, 0.18 mol) dropwise to the above-mentioned menthyl magnesium chloride tetrahydrofuran solution (prepared from 0.15 mol menthyl chloride) for 1.5 hours, after the addition is completed Keep stirring for 1.0h. Then filter to remove the MgCl generated by the reaction 2 solid, the resulting solution was directly subjected to the next reaction.

[0041] (2) Synthesis of L-menthol amide

[0042] At 20°C, add CuI (0.04g, 0.225mmol) and the ligand to the menthyl formate tetrahydrofuran solution obtained in (1) (0.076g, 0.225mmol), followed by ethylamine (7.4g, 0.165mol) to react for 2h. After the reaction is over, concentrate the reaction solution by vacuum distillation at 30°C until a small amount of solid precipitates, then drop it to -5°C within 2 hours, filter and dry to obtain the final product, L-menthyl amide, calculated as menthyl chloride The...

Embodiment 3

[0044] (1) Synthesis of Isobutyl L-menthyl formate

[0045] At 30°C, under the protection of N2 gas, add propyl chloroformate (19.8 g, 0.165 mol) dropwise to the above menthyl magnesium chloride solution (prepared from 0.15 mol menthyl chloride) for 2 hours, keep stirring after the addition is completed 2.0h. Then filter to remove the MgCl generated by the reaction 2 solid, the resulting solution was directly subjected to the next reaction.

[0046] (2) Synthesis of L-menthol amide

[0047] At 30°C, add CuOAc (0.05 g, 0.3 mmol) and the ligand to the tetrahydrofuran solution of menthyl formate obtained in (1) (0.12g, 0.3mmol), followed by ethylamine (7.1g, 0.16mol) to react for 3h. After the reaction, concentrate the reaction solution at 30°C by rectification under reduced pressure until a small amount of solid precipitates out, then drop it to 5°C within 3 hours, filter and dry to obtain the final product, L-menthyl amide, calculated as menthyl chloride Yield 90%. The p...

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Abstract

The invention discloses an ester ammonolysis reaction catalyst composition and a preparation method of L-menthane carboxamide. The ester ammonolysis reaction catalyst comprises a catalyst and a ligand, wherein the catalyst is cuprous salt CuX, the ligand is a (R)-N, N, N, N-tetraalkyl binaphthylamine compound shown as the specification, wherein R1, R2, R3 and R4 are independently selected from thegroups shown as the specification. Menthyl chloride is used as the starting raw material in the method to react with metal magnesium to prepare menthyl magnesium chloride, then reaction with chloroformate with different substituent groups is carried out to obtain menthyl formate, and then ammonolysis under the catalysis of an ester ammonolysis catalyst composition is conducted to obtain the L-menthane carboxamide. The yield is improved, the production cost is reduced, the optical purity is high, and environmental protection and no wastewater discharge are realized.

Description

technical field [0001] The invention relates to a catalyst composition for ester aminolysis reaction, and also relates to a preparation method of cooling agent L-menthol amide. Background technique [0002] Cooling agents are indispensable additives in people's daily life, and are widely used in the fields of food, daily chemicals, tobacco and medicine. For a long time, L-menthol has been the most familiar traditional cooling agent. L-menthol has the advantages of strong coolness, low threshold value and low price, but it also has some obvious disadvantages, such as strong pungent smell, bitter taste, not obvious cooling effect when the dosage is low, and when the concentration is large, there will be Burning sensation, strong volatility, short action time, etc., these shortcomings limit the application of L-menthol in many fields to a certain extent, especially in chewing gum and some special types of cosmetics. Therefore, people begin to seek more effective cooling agent...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/343C07C69/75B01J31/22
CPCC07C231/02C07C67/343B01J31/1805C07C2601/14B01J2531/16B01J2231/4283C07C233/58C07C69/75
Inventor 陈来中钟子太郭小安李文滨李晶何勇张永振
Owner WANHUA CHEM GRP CO LTD
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