890840-90-1

890840-88-7

890840-90-1

General procedure for the synthesis of 7,8-difluorobenzodihydropyran-4-one from 1,2-difluoro-3-(prop-2-yn-1-yloxy)benzene: The product of Example 82A (707 mg, 3.49 mmol) was stirred in a mixture of methanesulfonic acid (1 mL) and concentrated sulfuric acid (1 mL) at room temperature overnight. Upon completion of the reaction, the reaction was quenched with deionized water and extracted with ether. The combined ether extracts were washed sequentially with saturated sodium bicarbonate solution and brine, followed by drying with anhydrous sodium sulfate. The solvent was removed by concentration under reduced pressure to give Example 82B as a tan solid with a yield of 351 mg in 55% yield.