Guanidine: Studies on the reaction with ethyl N-(2-amino-1,2-dicyanovinyl) formimidate

Abstract

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.