A mixture of (4,4-dimethyl-1,4-dihydro-2-oxo-2H-3,1-benzoxazin-6-yl)boronic acid (4.2 g, 19.0 mmol), 3-cyano-5-methoxyphenyltriflate (5.1 g, 19.0 mmol), tetrakis(triphenylphosphine)-palladium (0) (1.1 g, 0.95 mmol), sodium carbonate (4.0 g, 38.0 mmol), and lithium bromide (5 g, 57 mmol) in DME (50 mL) and water (25 mL) was subject to a blanket of nitrogen for 15 minutes at 50° C. and then was heated at 85° C. for 1 hour. The reaction was cooled to room temperature and ethyl acetate (100 mL) was added. The organic layers were washed twice with aqueous ammonium chloride (100 mL) and once with brine (100 mL), dried over magnesium sulfate and concentrated. Purification via chromatography (silica gel, 40% ethyl acetate/hexane) gave 3-(4,4-dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6-yl)-5-methoxy-benzonitrile as a white solid (0.69 g, 53%): mp 254-255° C.; 1H-NMR (DMSO-d6) δ10.4 (s, 1H), 7.84 (s, 1H), 7.67-7.61 (m, 2H), 7.55 (bs, 1H), 7.4 (bs 1H) 6.99 (d, 1H, J=7.94 Hz), 3.88 (s, 3H), 1.67 (s, 6H); MS (EI) m/z 308 ([M+H]+, 30%); Anal. Calc. For C18H16N2O3: C, 68.13; H, 5.40; N, 8.83. Found: C, 68.03; H, 5.22; N, 8.46.
