Triethylamine → Mirogabalin

Participants

Reaction Steps

Tert-butyl[(1R,5S,6S)-3-ethyl-6-(nitromethyl)bicyclo[3.2.0]hept-3-en-6-yl]acetate (peak 1, 7.0 g, 23.7 mmol) was dissolved in ethanol (60 mL) and water (21 mL). To the solution, iron powder (13.27 g, 237 mmol) and ammonium chloride (628.1 mg, 11.9 mmol) were added, and the mixture was stirred for 5.5 hours under heating to reflux. The mixture was allowed to cool, then diluted with saturated saline, a saturated aqueous solution of sodium bicarbonate, and ethyl acetate, and filtered through Celite to remove insoluble matter. The filtrate was separated into organic and aqueous layers. The organic layer was washed with saturated saline and then dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure to obtain a pale yellow oil substance (7.02 g). This substance was dissolved in dichloromethane (200 mL). To the solution, (Boc)2O (5.25 g, 25 mmol) and triethylamine (5.01 g, 50 mmol) were added, and the mixture was stirred overnight at room temperature. The solvent was distilled off under reduced pressure, and the residue was then purified by silica gel chromatography to obtain the title compound of interest as a pale yellow oil substance (8.82 g, <100%).

Provenance & Evidence