Alkoxymethylene derivates 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, H-1 and C-13 NMR data are given.