N‐Acylamino acids and peptides V Improved synthesis of N‐Ferulylglycyl‐L‐Phenylalanine

Abstract As a result of difficulties with the synthesis of pure O‐(m)ethoxycarbonylferulyl chloride, N‐ferulylglycyl‐L‐phenylalanine (XVI) was previously prepared by a mixed anhydride method. However, due to the fact that analogous N‐acyl‐dipeptides were easily obtained by the acid chloride method, the synthesis of XVI was reinvestigated. After abortive tries to use the condensation of O‐p. bromophenacyl‐ferulyl chloride with N‐glycyl‐L‐phenylalanine t‐butyl ester, a method for the reproducible synthesis of pure 0‐ethoxycarbonylferulyl chloride was developed. Reaction of the latter substance with N‐glycyl‐L‐phenylalanine t‐butyl ester, followed by removal of the protecting groups from the condensation products, afforded N‐ferulylglycyl‐L‐phenylalanine in 51% yield. This last recovery compares favourably with the earlier published yield of 30%.