Reusable acidic nickel oxide nanoparticles have been synthesized,characterized and applied as a catalyst to convert 2-aminoaryl ketones and β-ketoesters/ketones into the corresponding quinolines in good yields with high selectivity.This could serve as a simple and convenient procedure for the Friedlander annulations. Reusable acidic nickel oxide nanoparticles have been synthesized, characterized and applied as a catalyst to convert 2-aminoaryl ketones and β-ketoesters / ketones into the corresponding quinolines in good yields with high selectivity. This could serve as a simple and convenient procedure for the Friedlander annulations.