A catalytic and green procedure for Friedlander quinoline synthesis in aqueous media

A green route for the synthesis of multi-substituted quinolines using catalytic amounts of Lewis acids via Friedlander annulation is described. Zr(NO3)4 and Zr(HSO4)4 were found to be more efficient than other investigated Lewis acids in the catalyzed condensation of o-aminoaryl ketones or o-amino benzonitrile with ketones or β-diketones in water under reflux conditions.