N-Hydroxyamide-Containing Heterocycles. New Effective Additives for Peptide Synthesis by the Dicyclohexylcarbodiimide Method.

N-Hydroxyamide-containing heterocycles, 1-hydroxy-4,6-dimethyl-2(1H)-pyrimidinone and -5,6-dimethyl-2(1H)-pyrazinone, are prepared. Judging from the result of model dipeptide (Z-Ala-Phe-OMe) formation, these compounds are found to be new effective additives for peptide synthesis by the dicyclohexylcarbodiimide (DCC) method at the points of high yield and no detectable racemization.