A SYNTHETIC APPROACH TO PEPTIDES OF O- AND P-AMINOBENZOIC ACIDS

Active esters of o-and p-aminobenzoic acids served as coupling components in peptide syntheses without concomitant protection of the relatively inert aromatic amino group. The products were then treated directly with benzyloxycarbonylamino acid symmetrical anhydrides to form higher peptide derivatives. An analogue of leucine-enkephalin with the glycylglycyl segment replaced by a p-aminobenzoyl residue has been synthesized by this route.