Method for synthesizing neotame

Abstract

The invention discloses a method for synthesizing neotame, which comprises the following steps of: introducing hydrogen gas with the pressure of 1 to 300KPa into 3,3-dimethyl butyraldehyde and aspartame in an organic solvent under the catalysis of an iridium-based catalyst and carrying out a hydrogenation reaction at the temperature of 10 to 40 DEG C for 5 to 30 hours; filtering to remove the iridium-based catalyst and concentrating filtrate to remove the organic solvent; and recrystallizing and purifying to obtain the neotame. The selectivity of the iridium-based catalyst adopted by the invention to imine is obviously better than the selectivity of the iridium-based catalyst to aldehyde during the catalytic hydrogenation reaction. The defect of low selectivity of palladium or platinum to the imine in the prior art is overcome, and acid also does not need to be added into a reaction system for acidification, so that the reaction progress is quickened by enhancing the pressure, the reaction time is shortened, and the generation of impurities is lowered. The utilization rate of raw materials is enhanced, the purity of the product of the neotame is enhanced, the purity of the product can be greater than 99 percent by simple crystallization, and the production cost is lowered.

Description

technical field [0001] The invention relates to a synthesis method of a food additive neotame. Background technique [0002] In recent years, the significant increase and rejuvenation of diabetic patients has become a growing concern. Therefore, many low-calorie sweeteners that can replace sucrose have been developed one after another. Aspartame is widely used as a safe sweetener with high sweetness. However, due to the poor thermal stability of aspartame, its application is subject to certain limitations. In U.S. Patent No. 5,480,668, an alkyl group is introduced into an amino group of aspartame to generate a new compound-new Sweet, its chemical name is N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine methyl ester, its structural formula is as follows: [0003] [0004] As the second-generation sweetener of aspartame, neotame has a sweetness 7000-13000 times that of sucrose and 50 times that of aspartame. Neotame has a pure sweetness similar to sucrose and good st...

AI Technical Summary

Problems solved by technology

[0007] Chinese patent CN101270092A discloses the N-alkylation reaction with formic acid, 3,3-dimethylbutyraldehyde and aspartame, but the reaction is not complete, and impurities that are difficult to separate will also be produced, and two alkanes are introduced N,N-bis(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine methyl ester, not suitable for large-scale production

This increases production costs

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