An improved procedure for the synthesis of glycine and taurine conjugates of bile acids

Glycine and taurine conjugates of 5beta-cholanic acids have been synthesized using improved procedures based on the peptide coupling reagent, N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline. The conjugates are obtained in chromatographically pure form in yields higher than 90%. The use of this procedure in the large scale preparation of cholyl[1,2-13C2]glycine is described.