REACTION OF TRYPTOPHAN WITH TRIFLUOROACETIC ANHYDRIDE

Article abstract of DOI:10.1016/S0040-4039(01)80754-1

Trifluoroacetic anhydride (TFAA) in ether quickly (=5-10 min) converted tryptophan to the crystalline 2-trifluoromethyl-5(4H)-oxazolone (2) without racemization.Dissolution of optically active 2 in acetonitrile gave racemic 2, whereas treatment with hot aqueous dioxane gave the isomeric oxazolone (3).Both 2 and 3, could on heating be further isomerized to the conjugated oxazolone (4).These oxazolones are interesting starting materials for the preparation of tryptophan containing peptides.