A New Method for the Synthesis of Carboxamides and Peptides Using 1,1′-Carbonyldioxydi[2(1H)-pyridone] (CDOP) in the Absence of Basic Promoters

Various carboxamides or peptides are synthesized from the corresponding carboxylic acids and amines or α-amino acids using 1,1′-carbonyldioxydi[2(1H)-pyridone]. The reaction proceeds in the absence of basic promoters such as triethylamine or 4-(dimethylamino)pyridine, therefore, the undesired racemization does not occur at all in the segment coupling producing Z-Gly-Phe-Val-OMe and Z-Phe-Val-Ala-OMe.