Boron trifluoride → Hydrochloric Acid

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of NaBH4 (16.0 g, 4.2 eq.) in tetrahydrofuran (125 mL) was added BF3 etherate (125 mL) at 0° C. The resulting reaction mixture was allowed to room temperature and stirred for 15 min 2-Chloro-3-[(E)-2-nitrovinyl]-6-(trifluoromethyl)pyridine (Int-19) (25.0 g, 1.0 eq) in tetrahydrofuran (125 mL) was added to above reaction mixture at room temperature. The reaction mixture was heated to 70° C. and stirred for 2 h. The resulting reaction mixture was allowed to room temperature and stirred for 16 h. The progress of the reaction was monitored by TLC. After completion of reaction, the reaction mixture was quenched in ice water (200 mL) and extracted with ethyl acetate (3×200 mL). The combined organic layers were washed with water (1×100 mL), brine (1×100 mL), dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure to get crude amine. The amine compound was dissolved in ethanolic HCl (50 mL) and stirred at room temperature for 2.0 h. The reaction mixture was concentrated under reduced pressure to get crude 2-[2-chloro-6-(trifluoromethyl)pyridin-3-yl]ethanamine (IIb-35) hydrochloride (15.0 g, 58.3%).

Provenance & Evidence