Potassium Carbonate → 6-(3-Ethynyl-phenyl)-4,4-dimethyl-1,4-dihydro-benzo[d][1,3]oxazin-2-one

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Reaction Steps

A mixture of 4,4-dimethyl-6-(3-trimethylsilanylethynyl-phenyl)-1,4-dihydro-benzo[d][1,3]oxazin-2-one (0.7 g, 2 mmol) and potassium carbonate (2 g, excess) in anhydrous methanol was stirred at rt under nitrogen for 4 hours. The mixture was treated with ice-water (100 mL) and extracted with ethyl acetate (2×80 mL). The organic layers were washed with brine and dried with MgSO4. The solvent was removed and the title compound was obtained as a off-white solid (0.4 g, 72%): mp 171-172° C. 1H-NMR (DMSO-d6) δ 10.3, (s, 1H), 7.78 (bs, 1H), 7.72-7.69 (m, 1H), 7.6-7.57 (m, 2H), 7.49-7.43 (m, 2H), 6.97 (d, 1H, J=7.98 Hz), 4.25 (s, 1H), 1.67 (s, 6H); MS (EI) m/z 277([M+], 100%), Anal. Calc. For C18H15NO2.0.2 EtOAc: C, 76.56; H, 5.67; N, 4.75. Found: C, 76.34; H, 5.4; N, 4.7.

Provenance & Evidence