Process for the preparation of n-alkylated dipeptides and their esters

Abstract From the Canadian patent

The invention relates to a process for the preparation of compounds of the formula I (I), in which n is 1 or 2, R represents hydrogen an aliphatic, cycloaliphatic, aromatic araliphatic, cycloaliphatic-, aliphatic radical or a radical ORa or SRa in which Ra, denotes alkyl, aryl or heteroaryl R1 denotes hydrogen, an aliphatic, cycloaliphatic-aliphatic aromatic, arali-, phatic, heteroaromatic radical or an aminoacid side chain R2 and R3 are identical or different and denote hydrogen an aliphatic, cycloaliphatic, aromatic or araliphatic radical, and R4 + R5, together with the atoms carrying them, form a heterocyclic ring system which comprises, reacting trifluoromethanesulfonic acid derivatives …