Hydrochloric Acid → 2-Nitroimipramine

Participants

Reaction Conditions

Reaction Steps

Imipramine (26a, 1.925 g, 6.87 mmol) was dissolved in 32 mL acetic acid and cooled to 18° C., Conc. nitric acid (0.79 mL, 13 mmol) in 1.1 mL acetic acid was added dropwise, with stirring, keeping reaction at 17°-18° C., then reaction stirred at that temperature for an additional 20 minutes. The reaction was then poured into 130 mL of 0.15M HCl and washed with Et2O (2×85 mL), then pH adjusted to 13 with conc. NaOH and extracted with CHCl3 (4×100 mL). The CHCl3 extracts were combined, washed with 85 mL brine, dried over Na2SO4, and solvent removed in vacuo. The residue was purified by column chromatography, eluting with THF/Hex/NH4OH (70/30/0.4) to yield 1.145 g (51%) of the desired 2-nitroimipramine (26b) as a red oil. 1H NMR (200 MHz, CDCl3)d 8.0-7.9 (m, 2H), 7.3-7.0 (m, 5H), 3.9 (t, 2H), 3.2 (s, 4H), 2.3 (t, 2H), 2.1 (s, 6H), 1.7 (p, 2H); mass spec (FAB) (M+H)+ 326.

Provenance & Evidence