Synthesis of methyl 7-aryl(hetaryl, cyclohexenyl)-10-(1,3-benzodioxol-5-yl)-8-oxo-7,8,9,10,11,12-hexahydro-benzo[b][1,7]phenanthroline-9-carboxylates

Three-component condensation of quinolin-5-amine with methyl 2-(1,3-benzodioxol-5-yl)-4,6-dioxocyclohexane-1-carboxylates and aromatic aldehydes (or cyclohex-3-ene-1-carbaldehyde) afforded new hexahydrobenzo[b][1,7]phenanthroline derivatives. The condensation in butan-1-ol is strictly regioselective but not stereoselective, so that mixtures of cis- and trans-isomeric methyl 7-aryl(hetaryl, cyclohexenyl)-10-(1,3-benzodioxol-5-yl)-8-oxo-7,8,9,10,11,12-hexahydrobenzo[b][1,7]phenanthroline-9-carboxylates at a ratio of ～40: 60% are formed.