Synthesis of Some New Hydroquinoline and Pyrimido[4,5-b] Quinoline Derivatives

A new series of hydroquinolines derivatives (1, 2) have been achieved by the cyclo condensation of 2 (4-methoxybenzylidenemalonitrile), aniline and dimedone in the presence of piperidene. Cyclization of 5,6,7,8-tetrahydro-4-(4-methoxyphenyl)-7,7-dimethyl-5-oxo-2-(phenylamino) quinoline-3-carbonitrile (2) sulphuric acid at room temperature afforded 7,8-dihydro-4-(4methoxyphenyl)-7,7-dimethylquinolin-5(6H)-one[2,3-b]2,3-dihydroquinolin-4 (1H)-one (3). Several substituted pyrimido[4,5-b]quinoline derivatives (4, 5, 6 and 7) were synthesized from 2-amino-1,4,5,6,7,8-hexahydro-4-(4-methoxphenyl)-7,7,-dimethyl-5-oxo-1-phenylquinoline-3carbonitrile (1) via cyclization with thiourea, chloroacetyl chloride, phenyl isothiocynate and formamide, respectively. The condensation of dimedone, with 4-methoxybenzylidene malononitrile in the presence of trimethylamine afforded 11-amino-3,4,8,9-tetrahydro-12-(4-methoxyphenyl)3,3,8,8-tetramethyl-2H-chromeno[2,3-b]quinoline-1, 10(7H,12H)-dione (8) but in ammonium acetate afforded 7,8-dihydro-4-(4-methoxyphenyl)-7,7-dimethylquinolin-5(1H,4H,6H)-one[2,3-b]4-amino-7,8dihydro-7,7-dimethylquinolin-5(6H)-one (9). The structures of the synthesized compounds were elucidated by elemental analyses and spectral data.