Theanine preparing process

Abstract

The present invention provides theanine preparing process. Under closed condition, L-pyroglutamic acid and anhydrous ethylamine react directly to produce theanine at temperature of 30-55 deg.c and pressure of 2-4 MPa. The preparation process uses marketable materials, and has safe and relaxed reaction condition, product yield over 20 %, product purity over 98 %, low production cost, less investment in apparatus, and is suitable for industrial production. What is more important is that all the side products of different steps may be reused in the next circulation, resulting in high comprehensive utilization and few environmental pollution.

Description

Technical field:

[0001] The invention relates to a preparation method of theanine. Background technique:

[0002] L-theanine (L-thiamine) is a characteristic amino acid of tea, which has various edible and medicinal functions. Its scientific name is N-ethyl-L-glutamine (N-ethyl-Lglutamine), and its structural formula is as follows:

[0003]

[0004] In 1942, Israeli Liechtenstein first used ethylamine and pyrrolidone acid to react in aqueous solution to obtain theanine in the laboratory. In 1951, Japan invented a method of using L-pyrrolidone acid and pure ethylamine (instead of dissolving in water) to react at low temperature, and the yield of theanine was increased, but the reaction time required a week or less. More than ten days, or even longer.

[0005] In the patent application number 02134857.X, a method for preparing theanine by reacting L-pyrrolidone acid and pure ethylamine in an atmosphere of inert gas is disclosed, the pressure is controlled at 6Mpa-12Mpa, a...

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