151668-40-5

118-93-4

407-25-0

151668-40-5

General procedure for the synthesis of 2-trifluoromethyl-4H-chromen-4-one from 2'-hydroxyacetophenone and trifluoroacetic anhydride: 2'-hydroxyacetophenone (0.01 mol) was dissolved in trifluoroacetic anhydride (0.02 mol), followed by addition of pyridine (0.01 mol) to the solution. The reaction mixture was heated and stirred at 80 °C for 3 hours. After completion of the reaction, it was cooled to room temperature and the reaction mixture was treated with 1 M hydrochloric acid (5 mL) and dichloromethane (5 mL), followed by thorough washing with distilled water. The organic layer was dried with anhydrous sodium sulfate, the solvent was removed by rotary evaporator and the residue was vacuum dried. The target product 2-trifluoromethyl-4H-chromen-4-one was isolated from the starting material by fast column chromatography using a hexane solution of 10% ethyl acetate as eluent if necessary.