Studies on the reaction of HOBt, HOOBt and HOSu with chloroalkane solventsand their affects on the peptide synthesis

HOBt, HOSu and HOOBt are the widely used reagents in the peptide synthesis, they are used as the activitor of carboxyl group and the inhibitor of race mization. HOBt, HOSu and HOOBt were found for the first time that they coul d react with chloroalkane solvents in the presence of different bases. The yields were related to the reaction condition such as the quantity and vari ety of bases, reaction temperature and the structure of the reactants. The more of the bases used, the higher of the yield and reaction speed. HOBt is more active than HOSu, CH2Cl2 is easy to form disubstituted products, ClCH 2CH2Cl is easy to form monosubstituted products. All of the products were p urified by chromatography on silica - gel, eight new compounds were identif ied by MS and H-1 NMR. In the model synthesis of dipeptide BocAlaPheOCH(3), the by - product was detected and the yield of the dipeptide was over 82%.