Ammonium Chloride → 3-Amino-5-bromo-2-chloropyridine

To a solution of 5-bromo-2-chloro-3-nitropyridine (10.0 g, 42.1 mmol) in EtOH (70 ml) and H2O (14 ml) was added iron (11.7 g, 211 mmol) and NH4Cl (6.76 g, 126 mmol) at room temperature. The mixture was refluxed for 1 hour, and then cooled to room temperature, filtered through a Celite pad and washed with EtOH. The filtrate was concentrated in vacuo. The residue was treated with saturated aq. NaHCO3, and extracted with EtOAc. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was purified by column chromatography (Hexane:EtOAc=3:1) to give 5-bromo-2-chloropyridin-3-amine (7.93 g, 91%) as a white solid. 1H-NMR (CDCl3, Varian 400 MHz) δ 5.89 (2H, s), 7.30 (1H, d, J=2.0 Hz), 7.66 (1H, d, J=2.4 Hz).

1. temperatureThe mixture was refluxed for 1 hour
2. filtrationfiltered through a Celite pad
3. washwashed with EtOH
4. concentrationThe filtrate was concentrated in vacuo
5. additionThe residue was treated with saturated aq. NaHCO3
6. extractionextracted with EtOAc
7. washThe combined organic layers were washed with brine
8. dry with materialdried over anhydrous Na2SO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue was purified by column chromatography (Hexane:EtOAc=3:1)

ORD record

ord-8f39b69dd59c484f9688b7a62ef0e843

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09422298B2