Nano TiO2@KSF as a high-efficient catalyst for solvent-free synthesis of Biscoumarin derivatives

A B S T R A C T : An efficient, simple and convenient route is described for the synthesis of biscoumarin (3,3'(arylmethylene)bis(4-hydroxy-2H-chromen-2-one)) by using recyclable catalyst TiO 2 @KSF. In this procedure, we synthesize a biscoumarin derivative via the three multi-component reactions (3MCRs) of two equivalent 4hydroxycoumarin with one equivalent of various aromatic aldehydes in the presence of 20 mg nano TiO 2 @KSF as homogeneous catalyst under solvent-free conditions at 100 °C for the convinced reaction times (8–15 min). e advantages of this protocol towards the synthesis of biscoumarin derivatives are: a) use of solvent-free conditions, b) inexpensive catalyst, c) using commercially available precursors, d) reusability of TiO 2 @KSF up to four cycles without much loss in reactivity, e) simple work-up, f) high yields of pure products, g) short reaction times. The structure of all biscoumarin derivatives were confirmed by M.p., TLC, FT-IR, 1 H NMR spectra and were compared with reliable references.