It was found later that heterocyclic guanidine analogs with p K a values shifted towards neutrality (e.g. 2-aminobenzimidazoles) are much better suited for this purpose. (uni-frankfurt.de)
Sodium2
The amidine formed with 2-naphthylamine and the dimethyl sulfate adduct can be cyclized with sodium methoxide to give benzo[f]quinoline (1-azaphenanthrene). (wikipedia.org)
The salt reacts also with cyclopentadiene in the presence of sodium amide in liquid ammonia to give the aminofulvene derivative. (wikipedia.org)
Group2
Derivatives of oxoacids RnE(=O)OH in which the hydroxy group is replaced by an amino group and the oxo group is replaced by =NR. Amidines include carboxamidines, sulfinamidines and phosphinamidines. (drugbank.com)
Amidines substituted with a benzene group. (nih.gov)