Nitromethane → Gabapentin

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium (5.1 mL of a 2.5 M solution in hexanes, 12.75 mmol) was added dropwise to a stirring mixture of nitromethane (0.34 mL, 6.3 mmol) in THF (20 mL) and HMPA (2 mL) at −78° C. under argon. The mixture was allowed to warm to −60° C. and stirred for 1 hour. The mixture was cooled to −78° C. and 3 (0.79 g, 5.73 mmol) was added. The mixture was allowed to warm to −60° C. and stirred for a further 2 hours. The mixture was quenched by addition of saturated ammonium chloride solution (5 mL). After warming to room temperature, dilute hydrochloric acid (10 mL) and ether (30 mL) were added. The organic layer was separated, and the aqueous layer was further extracted with ether (2×25 mL). The combined organic fractions were washed with brine, dried (MgSO4), and the solvent was evaporated under reduced pressure. The residue was chromatographed (SiO2, heptane/ethyl acetate, 95:5) to give the nitro-alcohol 1 (0.50 g, 43%) as a white solid; Rf (heptane/ethyl acetate, 9:1) 0.14; νmax(CH2Cl2)/cm−1 3424 (OH), 1548 (NO2), 1379 (NO2); δH (400 MHz; CDCl3): 4.45 (2H, s, CH2NO2), 3.26 (1H, s, OH), 2.04-1.95 (2H, m), 1.85-1.80 (4H, m), 1.64-1.24 (8H, m).

Provenance & Evidence