Abstract Alkoxymethylene derivatives I of 2, 4-pentanedione, 3-oxobutanenitrile, and methyl and ethyl 3-oxobutanoates with substituted 1-phenyl-5-aminobenzimidazoles and- benzotriazoles II give the products of nucleophilic substitution III and IV which, bearing ester groups, undergo thermal cyclizations to the corresponding 8-acetyl-3-phenyl-6, 9- dihydroazolo [4, 5-f] quinolin-9 (3H)-ones V and VI. IR, UV, 1 H and 13 C NMR data are ...