Highly Efficient Method for Solvent-Free Synthesis of Diarylmethane and Triarylmethane from Benzylic Alcohols Using P2O5/Al2O3 or P2O5/SiO2 at Room Temperature

A highly efficient procedure for the synthesis of triarylmethane and diarylmethane via benzylation of aromatic hydrocarbons from benzyl alcohols using supported P2O5 on SiO2 and/or Al2O3 under solvent-free conditions is described. Excellent yields of triarylmethane and diarylmethane were obtained using P2O5-SiO2 (50% W/W) and/or P2O5-Al2O3 (50% W/W) at room temperature. The reusability of both supported P2O5 on SiO2 and Al2O3 were examined. Both supported reagents show favorable activities in first and second runs, however, a decline in reactivity was observed in following attempts. The reaction is scalable to >0.03 mole amounts.Keywords: Diarylmethane, triarylmethane, aromatic alcohol, P2O5, silica gel, alumin