Boron trifluoride → Hydrochloric Acid

Temperature

70 °C

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%).

1. customThe resulting reaction mixture
2. customwas allowed to room temperature
3. additionwas added to above reaction mixture at room temperature
4. customThe resulting reaction mixture
5. customwas allowed to room temperature
6. stirringstirred for 16 h
7. customAfter completion of reaction
8. customthe reaction mixture was quenched in ice water (200 mL)
9. extractionextracted with ethyl acetate (3×200 mL)
10. washThe combined organic layers were washed with water (1×100 mL), brine (1×100 mL)
11. dry with materialdried over anhydrous sodium sulfate
12. customthe solvent was removed under reduced pressure
13. customto get crude amine
14. stirringstirred at room temperature for 2.0 h
15. concentrationThe reaction mixture was concentrated under reduced pressure

ORD record

ord-9fc429338ce347968b5967a371c4bc46

Source dataset

uspto-grants-2016_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09301526B2