A mixture of 5-[2-(cyclopropylmethoxy)-5-ethylsulfonylphenyl]-3-hydroxy-1-methylpyridin-2-one (50 mg, 0.14 mmol), sodium chlorodifluoroacetate (252 mg, 1.65 mmol), K2CO3 (70 mg, 0.51 mmol) in dioxane (4 mL) was stirred at 100° C. for 18 h. After the mixture was filtered, the filtrate was concentrated in vacuo. The residue was purified by prep-HPLC to give the title compound (16 mg, 28%) as a light pink solid. 1H NMR (CDCl3, 400 MHz) δ 7.84 (m, 1H) 7.77 (d, J=2.4 Hz, 1H) 7.63 (d, J=2.4 Hz, 1H) 7.49 (d, J=2.4 Hz, 1H) 7.04 (m, 1H) 3.95 (m, 2H) 3.69 (s, 3H) 3.13 (m, 3H) 1.33-1.26 (m, 4H) 0.72-0.67 (m, 2H) 0.39-0.36 (m, 2H). LCMS (M+H)+=414.
