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

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• 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: guanidines; mesoionic compounds; triaminoguanidinium salts; 1,2,4-triazolium-3-aminides; Introduction Easily accessible by

• metals [20]. In subsequent studies, Busch and co-workers found that a variety of 5-substituted 1,2,4-triazolium-3-aminides III (Scheme 1) can be prepared either in one step from triphenylaminoguanidine and acid chlorides at elevated temperatures or in two steps using an aldehyde and subsequent oxidation

• [21][22]. Several decades later, a range of diversely substituted 1,2,4-triazolium-3-aminides were prepared by condensation of N-amino-N-R-N’-phenylbenzamidines with phenylisocyanide dichloride [23] or 4-aryl-1,1-dibromo-2,3-diazabutadienes [24]. The 1,2,4-triazolium-3-aminides II and III belong to