A solution of 3-(Trifluoromethyl) benzene propanol (1.0 g, 4.90 mmol) in dichloromethane (20 ml) is cooled in a water/ice bath, treated in succession with DMSO (770 mg, 9.80 mmol) and P2O5 (1.39 g, 9.80 mmol) and left under stirring for 30 minutes, while temperature raises to 20°C. The reaction mixture is then cooled in water/ice bath and triethylamine (2.4 ml, 17.15 mmol). The resulting solution is kept under stirring while the temperature raises to 20°C. After one hour, the mixture is treated with 5 per cent HCl, the phases are separated, and the organic one is further washed with 5 per cent HCl. The organic phase is then washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to afford 0.99 g of the aldehyde of 3-(3-(Trifluoromethyl)phenyl)propanal in quantitative yield.
