A simple and green method is reported for the completely chemoselective synthesis of some new dicoumarol derivatives {3,3'-(2-aryl-2-oxoethylidene)bis[4-hydroxycoumarin]s} from the reaction of 4-hydroxycoumarin with arylglyoxals in a molar ratio of 2:1 respectively. The reactions efficiently promoted by titanium(IV) oxide nanoparticles as a heterogeneous catalyst via an on water process. Catalyst loading is very low and it shows recyclability.
Keywords: Titanium(IV) oxide nanoparticles, chemoselectivity, 3, 3'-(2-aryl-2-oxoethylidene)bis[4-hydroxycoumarin]s, catalysts, arylglyoxal.