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. 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 0.5M 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. The solvent was distilled off under reduced pressure to give N-tert-butoxycarbonyl-L-phenylalanine (286 mg.).

Provenance & Evidence