Expeditious and environmentally benign synthesis of imidazo[4,5,1-]quinolines sequential Povarov reaction/reductive cyclization.

In this contribution, a novel, simple, diastereoselective and environmentally benign two-step diversity-oriented synthesis of imidazo[4,5,1-]quinolines is described for the first time. The synthesis of the target compounds involves a deep eutectic solvent-mediated one-pot Povarov reaction leading to the obtention of 8-nitrotetrahydroquinolines, followed by a microwave-assisted reductive cyclocondensation employing different aromatic and aliphatic aldehydes. The target compounds were obtained in up to 70% overall yield starting from commercially available -nitroanilines, natural phenylpropanoids (-anethole and -isoeugenol) and aromatic or aliphatic aldehydes.