Borane → 2-(2,6-Difluorophenyl)ethan-1-amine

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Reaction Steps

2,6-Difluorophenylacetonitrile (15.8 g, 100 mmol) was dissolved in tetrahydrofuran (75 mL) at room temperature. The solution was cooled in an ice bath and borane.THF complex (100mL, 100 mmol) was added dropwise over 15 minutes under nitrogen atmosphere. The ice bath was removed after borane addition was complete and the mixture was stirred at room temperature for 23 hours under nitrogen atmosphere. Saturated aqueous ammonium chloride solution (20 mL) was added dropwise with stirring over 30 minutes. The reaction mixture was filtered through diatomaceous earth, concentrated to an oil, redissolved in ethyl acetate/water, and adjusted to pH 1.0 with concentrated hydrochloric acid. The mixture was filtered through diatomaceous earth and the ethyl acetate layer extracted with 1N hydrochloric acid (4×10 mL). The combined acidic aqueous extracts were washed with ethyl acetate (2×50 ml). Solid sodium chloride was added to the acidic aqueous extracts, adjusted to pH 9.0 with solid sodium bicarbonate and 5N sodium hydroxide solution, and the mixture extracted with methylene chloride (7×50 mL). The combined methylene chloride extracts were washed with brine solution, dried over anhydrous sodium sulfate, filtered, and concentrated to yield 10.6 g (68%) of the titled product as a nearly colorless oil:

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