Formimidate 1 was reacted with guanidinium chloride, at room temperature, in the presence of sodium ethoxide and in dilute THF solution, leading to pyrimidine 10 by an unusual intramolecular cyclization process. A different reaction mechanism operated when imidate 1 was combined with guanidinium acetate in nitromethane under reflux. Structure 14 is tentatively assigned to this new product.

Disubstituted o-phenylenediamines 10 were generated by reaction with ethoxymethylene malononitrile, ethyl ethoxymethylene cyanoacetate and diethyl 2-(ethoxymethylene)-malonate, followed by aromatic aldehydes. These compounds proved to be highly stable even under microwave irradiation. This feature, associated to a convenient substitution pattern, makes them suitable candidates to be tested for their biological activity or to be used as ligands for the preparation of metal complex catalysts.