High-yield synthesis method of n-ethyl-p-menthane-3-carboxamide

A synthesis method and a technology for menthamide, which are used in the preparation of carboxylic acid amides, chemical instruments and methods, preparation of organic compounds, etc., can solve the problems of complex synthesis routes and low yields, and achieve high yields, easy industrialization, and production. low cost effect

Inactive Publication Date: 2014-04-02
丁铁梅
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its advantages are less three wastes, safe operation, simple process, excessive ammonia in the reaction can be recycled and recycled, green and environmentally friendly, and its product has a long-lasting cool feeling and pure aroma, but the disadvantage is that the synthetic route is complicated and the yield is low

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1: (1) Add 16L tetrahydrofuran solvent, 14KG phosphorus pentachloride, and a composite catalyst composed of 0.7 KG aluminum trichloride hexahydrate, 0.08KG Ru-loaded catalyst, and 0.06KG alkali metal catalyst into the container and stir fully, Take 22L tetrahydrofuran solvent to dissolve 8.5KG L-menthol, slowly add it to the container under the condition of ice-water bath for reaction, after the reaction is complete, adjust the pH of the solution to 8 with sodium hydroxide, separate the organic phase, add anhydrous sulfuric acid Magnesium was dried and filtered. Heating and distilling the filtrate to remove the solvent with low boiling point to obtain L-chloromenthol; (2) Add 150 L toluene, 100KG L-chloromenthol, 48KG NaCN, 3KG phase transfer catalyst trimethylbenzyl ammonium chloride , the reaction solution was heated to 78 ~ 82 ℃, after 3 hours of reaction, the organic layer was washed 3 times with water, the toluene was evaporated first, and then the L-mentha...

Embodiment 2

[0016] Embodiment 2: (1) add 16LN in container, N-dimethylformamide, 14KG thionyl chloride, are made up of 0.7 KG aluminum trichloride hexahydrate and 0.08KG Ru supported catalyst, 0.06KG alkali metal catalyst The composite catalyst was fully stirred, and then 22L of tetrahydrofuran solvent was taken to dissolve 8.5KG of L-menthol, which was slowly added to the container for reaction in an ice-water bath. After the reaction was complete, the pH of the solution was adjusted to 8 with sodium hydroxide, and the organic phase, dried with anhydrous magnesium sulfate, and filtered. Heating and distilling the filtrate to remove the solvent with low boiling point to obtain L-chloromenthol; (2) Add 150 L toluene, 100KG L-chloromenthol, 48KG NaCN, 3KG phase transfer catalyst trimethylbenzyl ammonium chloride , the reaction solution was heated to 78 ~ 82 ℃, after 3 hours of reaction, the organic layer was washed 3 times with water, the toluene was evaporated first, and then the L-menthan...

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PUM

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Abstract

The invention discloses a high-yield synthesis method of n-ethyl-p-menthane-3-carboxamide. The method comprises the following steps: (1) adding a tetrahydrofuran solvent, phosphorus pentachloride and a composite catalyst into a container, fully stirring, dissolving L-menthol by the tetrahydrofuran solvent, and preparing L-chlorinated menthol; (2) heating and washing methylbenzene, L-chlorinated menthol, NaCN and a phase transfer catalyst-benzyltrimethylammonium chloride, distilling to obtain methylbenzene at first and then performing reduced pressure distillation to obtain L-menthyl nitrile; (3) performing heating reflux by polyphosphoric acid, triethyl phosphate and menthyl nitrile at 140 DEG C for 5 hours, cooling, adding distilled water, neutralizing to be neutral by a sodium hydroxide solution, extracting by ethyl ether, drying an organic phase by anhydrous magnesium sulfate, rotationally evaporating to remove the solvent, and re-crystallizing by acetone-water to obtain a finished product. According to the method, the menthyl nitrile intermediate yield is relatively high, a synthetic process is more reasonable, the comprehensive yield of the finished product can reach 75%, and the obtained finished product is relatively high in cool degree.

Description

technical field [0001] The invention belongs to the technical field of production of spices and cooling agents. More specifically, the present invention relates to a high-yield synthetic method of a cooling agent, particularly a menthyl amide. Background technique [0002] L-menthol, also known as menthol, is a kind of cooling agent that people are most familiar with, but because it is not resistant to high temperature, easy to volatilize, and the duration of cool taste is short, the instantaneous effect is strong and bitter, so it seriously affects the Its use effect and application field. Among many new cooling agents, menthyl amide has the advantages of low volatility and long-lasting cool taste. Its cooling intensity is 1.5 times that of menthol, and it has no bitterness and burning sensation. It is an ideal menthol Alternatives have attracted widespread attention in recent years. [0003] The currently reported process for synthesizing menthyl amide cooling agents wi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C233/58C07C231/06
Inventor 丁铁梅
Owner 丁铁梅
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