SYNTHESIS OF SUBSTITUTED DIPEPTIDE GB-115 AS A POTENTIAL SELECTIVE ANXIOLYTIC

摘要

A new potential selective anxiolytic GB-115 [N-(6-phenylhexanoyl)glycyl-L-tryptophan amide] has been prepared. The optimum method for GB-115 synthesis consists of five steps: (1) phenylhexanoylchloride synthesis using thionyl chloride; (2) glycine acylation with the resulting chloride under alkaline conditions at 0degC; (3) L-tryptophan esterification using thionyl chloride at room temperature; (4) N-(6-phenyl-hexanoyl)glycyl-L-tryptophan ethyl ester synthesis by the mixed anhydride method in dimethylformamide using isobutylchloro formate; (5) ammonolysis of the resulting dipeptide ester with gaseous ammonia in methanol. The activated ester and carbodiimide methods were also studied in addition to the mixed anhydride method with various solvents and different ways of product extraction.