Process for synthesis of L-glutamine

Abstract

Disclosed is a process for synthesis of L-glutamine which consists of, reacting ortho-phthalic anhydride and excess L-glutamine at 120-180 deg. C, obtaining phthaloyl-L-glutamine and L-pyroglutamic acid, separating to obtain L-pyroglutamic acid and phthaloyl-L-glutamine, subjecting the latter and acetic anhydride to azeotropy 3-30 minutes to form phthaloyl-L-glutamic acid anhydride, acting with stronger ammonia water directly at room temperature, obtaining phthaloyl-L-glutamine, charging hydrazine hydrate solution, dispensing 48 hours to remove the protective groups.

Description

1. Technical field

[0001] The invention relates to a synthesis method of L-glutamine, which belongs to the technical field of chemical synthesis. 2. Technical background

[0002] L-glutamine (L-glutamine) is the most abundant free amino acid in mammalian plasma, which has many important physiological functions. Its structural formula is: NH 2 COCH 2 CH 2 CH(NH 2 )COOH. According to current literature reports, the chemical synthesis of L-glutamine mainly has the following six approaches:

[0003] 1. L-glutamic acid-γ-methyl ester method of protecting amino groups with carbon disulfide. In this method, L-glutamic acid and methanol are first formed into an ester, and then carbon disulfide is added to react with the amino group to form ammonium aminodithioformate to protect the amino group, and ammonia gas is introduced until saturation, left for 4-5 days, and then concentrated under reduced pressure Remove ammonia, add glacial acetic acid to remove carbon disulfide, evapo...