Acetic Acid → L-Theanine

Participants

Reaction Conditions

Reaction Steps

First, 20.0 g (0.124 mol) of L-glutamic acid-γ-methyl ester was suspended in 20 g of methanol. To this, 13.7 g (0.137 mol) of acetylacetone and 12.5 g (0.124 mol) of triethylamine were added. The mixture was stirred at 60° C. for one hour. Subsequently, 80 g (1.24 mol) of 70% ethylamine was added to the mixture. After the mixture was allowed to react for 6 hours, excessive ethylamine was distilled away under reduced pressure. To this, 29.8 g (0.496 mol) of acetic acid, 30 mL of water and 120 mL of IPA were added. The mixture was heated for one hour and cooled on ice. The crystal precipitated was filtrated by suction and washed with 20 mL of IPA to obtain wet matter. The wet matter was dried under reduced pressure to obtain 13.1 g of theanine as a white crystal substance (yield: 61%). The obtained theanine had the same purity as high as in Example 1.

Provenance & Evidence