Abstract
N-methylimidazole (MeIm) activates stable condensing reagents such as 2,4,6-triisopropylbenzenesulfonyl-4-nitroimidazolide (TPSNI) and mesitylene-sulfonyl-4-nitroimidazolide (MSNI). Fully protected trinucleotides which could serve as key intermediates were synthesized by using MeIm and TPSNI or MSNI. These trinucleotides were utilized in the syntheses of the dodecamers, dCATCCACCCCAT and dAGCCATCTGCTT, which correspond to the specific tetrapeptides of cholecystokinin-pancreozymin and vasoactive intestinal peptide.