Citric Acid → L-Phenylalanine, N-[(1,1-dimethylethoxy)carbonyl]-

Participants

Reaction Steps

A solution of ethyl 2-tert-butoxycarbonyloxyiminoacetoacetate (646 mg.) in a mixture of tert-butyl alcohol (5 ml.) and water (5 ml.) was added at once to a solution of L-phenylalanine (330 mg.) and triethylamine (0.28 ml.) in a mixture of tert-butyl alcohol (8 ml.) and water (8 ml.) at room temperature, and the mixture was stirred for 2 hours at room temperature. Water (100 ml.) was added to the reaction mixture and the mixture was adjusted to pH 7 with a 0.5 M citric acid aqueous solution and washed twice with ethyl acetate (40 ml). The aqueous layer was adjusted to pH 3 with a 0.5M citric acid aqueous solution, followed by addition of a sodium chloride aqueous solution, and extracted twice with ethyl acetate (40 ml.). The extract was washed with water and dried, and the solvent was distilled off under reduced pressure to give N-tert-butoxycarbonyl-L-phenylalanine (286 mg.).

Provenance & Evidence