Rapid procedure for N-phthaloylation of alpha-amino carboxamides, alpha-amino alcohols, alpha-amino esters and dipeptide derivatives

A rapid, one-pot synthesis and mild procedure for the N-phthaloylation of a lpha -amino carboxamides is described. In acetonitrile, these derivatives r eact with mono-methylphthalate in the presence of BOP and i-Pr2NEt to affor d the intermediate N-alpha-[(o-methoxycarbonyl)benzoyl] amino carboxamides, which undergo rapid cyclization in the presence of aqueous sodium carbonat e to afford the corresponding N-alpha-phthaloyl amino carboxamides in excel lent yields. The reaction also works efficiently with alpha -amino esters, alpha -amino alcohols and dipeptide esters or amides.