Hydrochloric Acid → (αR)-4-Chloro-2-fluoro-α-methylbenzenemethanamine

Participants

Reaction Steps

To a solution of (S)-N-((R)-1-(4-chloro-2-fluorophenyl)ethyl)-2-methylpropane-2-sulfinamide (5.4 g, 19.4 mmol) in methanol (150 mL) at 0° C. was added a solution of hydrochloric acid in p-dioxane (4.0 M in p-dioxane, 19.4 mL, 77.6 mmol). The reaction was slowly warmed to room temperature and stirred at room temperature for 18 h. The solvent removed in vacuo, and the crude material was dissolved in saturated aqueous sodium bicarbonate and dichloromethane. The mixture was stirred for 45 min to give a clear solution. The phases were separated, and the aqueous layer was extracted with dichloromethane (2×100 mL). The combined organic layers were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was used without further purification (3.1 g, 92%, >96% ee, determined by Mosher's method).

Provenance & Evidence