Ethyl Acetate → 6-(3-Chloro-4-fluoro-phenyl)-8-fluoro-4,4-dimethyl-1,4-dihydrobenzo[d][1,3]oxazin-2-one

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Reaktionsschritte

A mixture of 6-bromo-8-fluoro-4,4-dimethyl-dihydro-benzo[d][1,3]oxazin-2-one (0.176 g, 0.64 mmol), 4-fluoro-3-chlorophenyl boronic acid (0.15 g, 0.84 mmol), tetrakis(triphenylphosphine)-palladium (0) (0.04 g, 0.032 mmol), and sodium carbonate (0.20 g, 1.92 mmol) in DME (10 mL) and water (5 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 mixture was cooled to room temperature and ethyl acetate (100 mL) was added. The organic layer was washed twice with aqueous ammonium chloride (100 mL) and once with brine (100 mL), dried over magnesium sulfate and concentrated. The residue was purified via chromatography (silica gel, 25% ethyl acetate/hexane) to give 6-(3-chloro-4-fluoro-phenyl)-8-fluoro-4,4-dimethyl-1,4-dihydrobenzo[d][1,3]oxazin-2-one as a white solid (0.13 g, 66%): mp 246-248° C.; 1H-NMR (DMSO-d6) δ10.5 (s, 1H), 8.00 (dd, 1H, J=7.09, 2.32 Hz), 7.78-7.73 (m, 1H), 7.62 (dd, 1H, J=11.86, 1.77 Hz), 7.7 (t, 2H, J=9 Hz), 1.7 (s, 6H); MS (APCI) m/z 324 ([M+H]+, 100%); Anal. Calc. For C16H12F2NO2.0.5 H2O: C, 57.76; H, 3.94; N, 4.21. Found: C, 57.49; H, 3.69; N, 4.03.

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