Abstract Quinazolin-4 (3H)-ones, 1, 2-dihydroquinazolin-4 (3H)-ones, 3, 4- dihydroquinazolines, imidazo [1, 2-c]-quinazolines and 5, 6-dihydroimidazo [1, 2-c] quinazolines were synthesized by the novel reductive reaction of nitro group, NH bond and ortho-ester, aldehydes or ketones promoted by the low-valent titanium reagent (TiCl 4-Zn system). The structures of these compounds were characterized by elemental analysis, IR ...