Potassium Carbonate → 8-Bromo-2-methyl-3,4-dihydro-2H-1,4-benzoxazin-3-one

Participants

Reaction Steps

A mixture of 2-bromo-N-(3-bromo-2-hydroxyphenyl)propanamide (4.72 g, 14.61 mmol) and potassium carbonate (2.020 g, 14.61 mmol) in DMF (50 mL) was stirred at room temperature overnight. At the conclusion of this period, the reaction mixture was diluted with water and extracted with ether. The organic layer was dried over anhydrous MgSO4, filtered, and concentrated. The resulting residue was purified by flash chromatography (100:0:0 to 0:90:10 hexanes:ethyl acetate:methanol) to afford the title compound (3.35 g, 95% yield) as a brown solid. 1H NMR (400 MHz, CDCl3) δ 8.17 (br. S, 1H), 7.22 (dd, J=8.0, 1.4 Hz, 1H), 6.85 (t, J=7.9 Hz, 1H), 6.76 (dd, J=7.8, 1.4 Hz, 1H), 4.78 (q, J=6.8 Hz, 1H), 1.64 (d, J=6.8 Hz, 3H).

Provenance & Evidence