TiO2 nanoparticles as an effective catalyst for the synthesis of hexahydro-2-quinolinecarboxylic acids derivatives

The one-pot three-component reaction of arylmethylidenepyruvic acids, 1,3-cyclohexandiones and ammonium acetate provides an economical and efficient synthetic route to 5-oxo-4-aryl-1,4,5,6,7,8-hexahydro-2-quinolinecarboxylic acid 4 under solvent-free conditions using a catalytic amount of TiO2 nanoparticles (TiO2 NPs) as an effective heterogeneous catalyst.