Orthoamides by selective borohydride reduction of N,N′,N″-triacyl- and N,N′,N″-tri(alkoxycarbonyl)-guanidines.

Graphical abstract Highlights • Triacylated guanidines are reduced to orthoamides by borohydride. • TriBOC guanidine was over-reduced by borohydride to aminal. • Guanidine tricarbamates also reduce to orthoamides by borohydride. Abstract N , N ′, N ″-Triacylguanidines and N , N ′, N ″-tri(alkoxycarbonyl)guanidines were prepared and reduced with borohydride salts in a mixture of tetrahydrofuran and acetic acid to give triacyl and tri(alkoxycarbonyl) orthoamides in yields of 40–85%. However, similar reduction of N , N ′, N ″-tri(t -butoxycarbonyl)guanidine did not give orthoamide but the aminal di(t -butyl) methylenedicarbamate. [ABSTRACT FROM AUTHOR]