Hydrochloric Acid → 2,2-Difluoro-2-phenylethylamine

Participants

Reaction Steps

Borane·dimethylsulfide (1.5 ml; 15.4 mmol) was added dropwise over 30 minutes to a solution of the title compound of Step (B) (1 g; 5.84 mmol) in 6 ml of THF at room temperature. After stirring 18 hr at room temperature and 2 hr at reflux, the reaction mixture was cooled to 0° C. and 3 ml of methanol were added carefully over 15 minutes. The solution was saturated with HCl (g) and the cloudy mixture was stirred 6 hr at room temperature, 30 minutes at reflux and 60 hr at room temperature. After removing the volatiles in vacuo, the residue was partitioned between ether (50 ml) and 1N HCl (30 ml). The ether layer was extracted with 1N HCl (10 ml) and the combined aqueous was backwashed with ether (50 ml). After adjusting the pH to 8 with solid NaHCO3, 1N NaOH (1 ml) was added and the aqueous layer was extracted with ether (50 ml). After washing with saturated NaHCO3 solution (25 ml), water (25 ml) and brine (25 ml), the ether layer was dried (MgSO4) and concentrated to afford 355 mg (39%) of the title compound of this step as a colorless liquid.

Provenance & Evidence