8-bromo-3,3-dimethyl-2,3-dihydropyrido[3,2-b][1,4]oxazepin-4(5H)-one → 8-Bromo-3,3-dimethyl-2,3,4,5-tetrahydropyrido[3,2-b][1,4]oxazepine

Participants

Reaction Steps

To a solution of 3-bromo-7,7-dimethyl-6,7-dihydro-9H-5-oxa-1,9-diaza-benzocyclohepten-8-one (620 mg, 2.28 mmol) in THF (15 mL) was added BH3 (9.1 mL of a 1 M solution in THF, 9.1 mmol), and the mixture was heated to reflux overnight. After cooling, the solvent was removed in vacuo. The residue was dissolved in MeOH (15 mL) and 2 N NaOH (5 mL), and the mixture was heated to reflux for 4 h. Methanol was then removed in vacuo and the resulting precipitate was collected by filtration to give the title compound (260 mg, 44%) as a white solid: 1H NMR (300 MHz, CDCl3) δ 7.78 (d, J=1.8 Hz, 1H), 7.19-7.18 (m, 1H), 4.60 (br s, 1H), 3.83 (s, 2H), 3.10 (d, J=3.9 Hz, 2H), 1.03 (s, 6H); ESI MS m/e 257 (M+H)+.

Provenance & Evidence