Iron(III)chloride induced synthesis of pyrazolopyridines & quinolines

A simple and straightforward protocol has been accomplished for synthesis of pyrazolo[3,4-b]pyridines by reacting 5-amino-1-phenyl-3-(trifluoromethyl)-1H-pyrazole-4-carbaldehyde (1) and β-enaminoketones (2) promoted by Iron(III)chloride. This protocol was also able to produce quinolines (5) by the reaction of O-nitrobenzaldehydes and β-enaminoketones. Simple reaction conditions, high compatibility and excellent yields are the advantages of this protocol.