7-bromo-2,2-dimethyl-2H,3H,4H-pyrido(3,2-b)(1,4)oxazin-3-one → 7-bromo-2,2-dimethyl-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-bromo-2,2-dimethyl-4H-pyrido[3,2-b][1,4]oxazin-3-one (0.360 g, 1.39 mmol) in THF (8.9 mL) at 0° C. was added BH3 (8.43 mL of a 1.0 M solution in THF, 8.43 mmol). The solution was heated to reflux. After 18 h, the solution was cooled to 0° C. and the reaction quenched with MeOH (15 mL). The mixture was concentrated and the resulting off-white solid was dissolved in MeOH (15 mL) and NaOH (10 mL of a 1 N solution). The mixture was heated at reflux to 4 h. The MeOH was removed under reduced pressure. The resulting precipitate was collected by filtration and washed with H2O (10 mL). The white solid was dried to give the title compound (0.260 g, 76%) as white needles: 1H NMR (300 MHz, DMSO-d6) δ 7.62 (d, J=2.1 Hz, 1H), 7.10 (d, J=1.5 Hz, 1H), 7.03 (br s, 1H), 3.14 (d, J=2.4 Hz, 2H), 1.25 (s, 6H); MS (ESI) m/e 243 (M+H)+.

Provenance & Evidence