Synthesis of some 1-{2-(phthalimido-N-oxy)-ethyl} derivatives of 4-(4-substituted phenyl)-2,6-dimethyl-1,4-dihydro-3,5-bis-N-(4-oxo-2-phenylquinazolin-3(4H)-ylcarboxamides

摘要

A series of 1-{2-(phthalimido-M-oxy)-ethyt}-4-(4-substituted phenyl)-2,6-dimethyl-1,4-dihydro-3,5-bis-N-(4-oxo-2-phenylquinazolin-3(4H)-ylcarboxamides (6a-d) have been synthesized via a multistep reaction sequence. Ethyl acetoacctate, various araldehydes and ammonia were condensed in ethanol to yield diethyl 4-(4-substituted phenyl)-2,6-dimcthyl-1,4-dihydropyridine-3,5-dicarboxylate (2a-d). Ester group of these 2a-d was replaced by hydrazine hydrate in dioxane to give 4-(4-substituted phenyl)-2,6-dimethyl-1,4-dihydropyricline-3,5-dicarbohydrazidc (3a-d). These were further treated with benzoxazine-4(3H)-one to give 4-(4-substituted phenyl)-2,6-dimethyl-1,4-dihydro-3,5-bis-n-(4-oxo-2-phenylquinazolin-3(4H)-ylcarboxamidcs (4a-d). Final compounds 6a-d were obtained by refluxing, 4a-d with bromoethoxyphthalimide (5). The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, ~1H NMR and mass spectral data.