Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

Beilstein J Org Chem. 2017 Mar 22:13:579-588. doi: 10.3762/bjoc.13.57. eCollection 2017.

Abstract

Depending on the reaction conditions, N,N',N''-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form either symmetrical N,N',N''-tris(N-acyl-N-benzylamido)guanidines 6 or mesoionic 4-amino-1,2,4-triazolium-3-hydrazinides 7. The latter were converted into 1,2,4-triazolium salts by protonation or methylation at the hydrazinide nitrogen atom. Neutral 1,2,4-triazoles 10 were obtained by catalytic hydrogenation of an N-benzyl derivative. Crystal structure analyses of a 4-benzylamino-1,2,4-triazolium-3-hydrazinide and of two derived 1,2,4-triazolium salts are presented.

Keywords: 1,2,4-triazolium-3-aminides; guanidines; mesoionic compounds; triaminoguanidinium salts.