6-quinolinylamine condensation with aldehydes and methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate

Abstract

A condensation of methyl 2,2-dimethyl-4,6-dioxocyclohexanecarboxylate with 6-quinolinylamine and aldehydes of aromatic (heteroaromatic, alicyclic) series gave rise to new derivatives of 4,7-phenanthroline. The condensation in ethanol proceeded regioselectively and with a high extent of stereoselectivity leading to the formation of a mixture of cis- and trans- methyl 9,9-dimethyl-12-aryl (heteryl, cyclohexenyl)-11-oxo-7,8,9,10,11,12-hexahydrobenzo[b]-4,7-phenanthroline-10-carboxylates. In the more severe conditions both regio- and stereoselectivity of the process decreased resulting in the formation of a mixture of 8- and 10-methoxycarbonyl derivatives (∼1:2), and somewhat grew the fraction of the cis-isomers in the mixture.