Borane;tetrahydrofuran → 7-Nitro-3,4-dihydro-2H-1,4-benzoxazine

Participants

Reaction Conditions

Reaction Steps

Mix 7-nitro-4H-benzo[1,4]oxazin-3-one (2.00 g, 10.3 mmol) in THF (10 mL) and treat with BH3.THF (1.0M in THF, 35 mL). Heat the solution to reflux for 30 min, then cool to 0° C. and quench with 1N HCl (20 mL). Stir the solution for 30 min, then concentrate to ½ volume. Collect the orange solid, wash with water, and dry under vacuum to give the title compound (1.66 g, 89%). MS (ES+) 181.1 (M+1)+, MS (ES−) 179.2 (M−1)−. 1H NMR (400 MHz, DMSO-d6): δ 7.68 (dd, 1H, J=8.8, 2.6 Hz), 7.53 (s, 1H), 7.47 (d, 1H, J=2.6 Hz), 6.63 (d, 1H, J=9.2 Hz), 4.15 (t, 2H, J=4.4 Hz), 3.44-3.40 (m, 2H),

Provenance & Evidence