A mixture of 6-chloro-4-methyl-4-trifluoromethyl-1,4-dihydro-benzo[d][1,3]-oxazin-2-one (0.2 g, 0.75 mmol), 3-methoxyphenyl boronic acid (0.13 g, 0.9 mmol), potassium phosphate (0.23 g, 1.1 mmol), and nickel (II) (diphenylphosphino)ferrocenyl dichloride (52 mg, 0.076 mmol) in anhydrous dioxane was subject to a blanket of nitrogen to remove oxygen and heated at 95° C. under nitrogen for 48 hours. Another portion of 3-methoxyphenyl boronic acid (0.13 g, 0.9 mmol) and Nickel (II) (diphenylphosphino)ferrocenyl dichloride (52 mg, 0.076 mmol) was added and the reaction solution was heated at 95° C. under nitrogen for a further 48 hours. The reaction solution was cooled to room temperature. Saturated aqueous ammonium chloride solution (30 mL) and ethyl acetate (50 mL) was added. The organic layer was separated and the aqueous layer was extracted with ethyl acetate (3×20 mL). The combined organic layer was washed with brine and dried (MgSO4). After removal of solvent, the residue was purified by a flash chromatography (silica gel, hexane:ethyl acetate/4:1) to afford the title compound as a white solid (50 mg, 20%): mp 178-179° C.; 1H-NMR (DMSO-d6) δ10.85 (bs, 1H, D2O exchangeable), 7.73 (m, 2H), 7.38 (t, 1H, J=7.9 Hz), 7.23 (d, 1H, J=7.7 Hz), 7.19 (d, 1H, J=1.9 Hz), 7.02 (d, 1H, J=8.2 Hz), 6.94 (dd, 1H, J=8.2, 2.4 Hz), 3.88 (s, 3H), 1.98 (s, 3H); 19F-NMR (DMSO-d6) δ−81.88 (s, 1F); Anal. Calc. For C17H14F3NO3: C, 60.54; H, 4.18; N, 4.15. Found: C, 60.58; H, 4.44; N, 4.19.
