AN IMPROVED SYNTHESIS OF TAURINE-CONJUGATED AND GLYCINE-CONJUGATED BILE-ACIDS

A simple and efficient method for the synthesis of taurine- and glycin e-conjugated bile acids is described. The condensation reaction was ac hieved by the simple mixing of unconjugated bile acid (1.0 eq.), tauri ne (2.0 eq.) (or glycinate ester), diethyl phosphorocyanidate (1.2 eq. ) in the presence of triethylamine at room temperature for 30-60 min. Sample clean-up was effected by the use of a prepacked Sep-Pak C-18 ca rtridge for reversed-phase solid extraction or by direct recrystalliza tion, yielding the desired taurine and glycine conjugates in 89-93 and 92-96% isolated yields, respectively.