反应详情

Sodium triacetoxyborohydride (1.02 g, 4.82 mmol) was added to 2-Nitro-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene (0.312 g, 1.61 mmol) in Acetonitrile (15 mL) and Acetic acid (0.20 mL, 3.5 mmol), then 13 M of Formaldehyde in Water (0.60 mL) was added. After 45 min, the mixture was poured into 100 mL EtOAc and washed with satd. sodium bicarbonate (3×30 mL) and brine (50 mL). After drying over sodium sulfate and conc. the residue was chromatographed (ISCO, 40 g, 0-40% EtOAc:Hex) to afford 9-Methyl-2-nitro-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene as an orange solid (298 mg, 89%). 1H-NMR (CDCl3): 7.65 (d, 1H, J=8.6 Hz), 7.61 (s, 1H), 6.91 (d, 1H, J=8.6 Hz), 4.29 (t, 2H, J=5.8 Hz), 3.33 (t, 2H, J=6.0 Hz), 2.86 (t, 3H), 2.08 (tt, 2H, J=5.8, 6.0 Hz)

1. washwashed with satd
2. dry with materialAfter drying over sodium sulfate
3. customconc. the residue was chromatographed (ISCO, 40 g, 0-40% EtOAc:Hex)