7-Hydroxy-4-(trifluoromethyl)coumarin

7-Hydroxy-4-(trifluoromethyl)coumarin can be used as a reference standard for fluorescent pH indicator.

372-31-6

108-46-3

575-03-1

GENERAL METHOD: Iodine (25 mol%) was added to a mixture of resorcinol (5 mmol) and ethyl 4,4,4-trifluoroacetoacetate (6 mmol) in toluene (1 mL). The reaction mixture was heated and stirred at 90 °C for 18 h. The progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, the mixture was cooled to room temperature, diluted with ethyl acetate (10 mL) and washed with distilled water (10 mL). The combined organic layers were dried with anhydrous sodium sulfate and the solvent was removed by evaporation under reduced pressure. The product was purified by fast column chromatography (silica gel, eluent: hexane/ethyl acetate = 95/5 to 80/20).