Synthetic method of cooling agent N-, 2, 3-trimethyl-2-isopropyl butyrylamide

Abstract

The invention relates to a synthetic method of cooling agent N-, 2, 3-trimethyl-2-isopropyl butyrylamide. The method comprises the following steps: respectively adding 2, 2-isopropyl propionitrile, alcohol and acid into a 500 mL high-pressure reactor according to the mole ratio of 2, 2-isopropyl propionitrile, alcohol and acid gas of 1: (3-5): (3-5), performing backflow under stirring, reacting for 4 to 10 h, recycling excess acid gas and alcohol, cooling, washing sodium bicarbonate for two times, extracting saturated sodium chloride solution, standing, and performing liquid separation and drying, so as to obtain 2, 3-trimethyl-2-isopropyl butyric ester; respectively adding 2, 3-trimethyl-2-isopropyl butyric ester, amine and basic catalyst into a 500 mL high pressure reactor according to the mole ratio of 2, 3-trimethyl-2-isopropyl butyric ester, amine, basic catalyst of 1: (1.5-5): (0.04-0.3), washing, adding organic solvent to perform recrystallization, and then obtaining the cooling agent N-, 2, 3-trimethyl-2-isopropyl butyrylamide, wherein the content is 99.31 percent, and the yield is 87.32 percent. The method has the advantages that intermediate transformation rate is high, a small quantity of three wastes are produced, the method is safe to operate, the process is simple, amine can be circularly applied mechanically, the method is green and environmentally friendly, and the cold sense of products is lasting.

Description

technical field [0001] The invention relates to the field of food additive preparation, in particular to a method for synthesizing an amide cooling agent. technical background [0002] The cooling agent N,2,3-trimethyl-2-isopropylbutanamide (WS-23) is a non-menthol amide cooling agent widely used. Its cooling effect is not as strong as menthol but it is non-irritating. , Widely used in daily chemical, food, medicine, tobacco and other industries. [0003] The reported technology of using 2,2-isopropylpropionitrile as an intermediate to synthesize cooling agent WS-23 is to hydrolyze 2,2-isopropylpropionitrile into 2,3-trimethyl-2- Isopropylbutanoic acid, acid chlorination, and finally react with methylamine to obtain the target product, or use 2,2-isopropylpropionitrile as raw material to react with methanol under the catalysis of concentrated sulfuric acid or chlorosulfonic acid to obtain the target compound . [0004] For example, the patent US 4230688 discloses Wilkinso...

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Problems solved by technology

The disadvantage of changing the process is that it produces more three wastes, the safety is poor, and the process is complicated and does not conform to green chemistry.

[0005] Disclosed as patent US 6482983 the synthetic technique of U.S. Millennium Specialty Chemicals company and the 6th issue of spice fragrance cosmetics in December, 2007 " novel cooling agent N, 2, 3-trimethyl-2-isopropyl butyramide (WS- 23) Synthesis of Li Jiayu and Zhang Chi reported that 2,2-isopropylpropionitrile is used as an intermediate, and the product is obtained by one-step reaction with methanol under the condition of concentrated sulfuric acid or chlorosulfonic acid as a catalyst. The process is similar to that in Li The disadvantage of this process is that the conversion rate of intermediates is low, there are many wastes, and there are many impurities in the reaction, which are difficult to remove and affect the coolness of the product.

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