Heterocyclic compounds with a bridgehead nitrogen atom. Synthesis in the imidazo[1,2-c]quinazoline series

The structures of imidazo1,2-c]quinazolines were reexaminated and established by spectroscopic studies with the aid of high-field ¹H and ¹³ C nmr and mass spectra. In acidic media, 3 reacts to give the products of electrophilic substitution reaction and ring opening compound 5 , leading to the imidazo1,2-c]benzoe]-1,2,3]triazine ring.