5-Bromo-3-nitropyridine-2-carbonitrile → 3-Amino-5-bromopyridine-2-carbonitrile

Temperature

80 °C

Iron powder (5.0 g, 90 mmol) was added to a solution 5-bromo-3-nitropyridine-2-carbonitrile (4.56 g, 20 mmol) in glacial acetic acid (125 ml). The suspension was stirred for 2 h at 80° C. The cooled mixture was filtered through a short plug of Celite and washed with EtOAc. Solvents were evaporated, the residue was dissolved in EtOAc and neutralised with 20% aqueous K2CO3. Phases were separated and organic phase was washed with water and brine, dried over anhydrous Na2SO4, filtered and evaporated. Crude product was purified by CombiFlash (DCM-MeOH, gradient elution). Product fractions were combined and evaporated to produce 1.67 g of product. 1H-NMR (400 MHz; d6-DMSO): δ 6.55 (s, 2H), 7.46 (d, 1H, J=2.0 Hz), 7.94 (d, 1H, J=1.9 Hz).

1. filtrationThe cooled mixture was filtered through a short plug of Celite
2. washwashed with EtOAc
3. customSolvents were evaporated
4. dissolutionthe residue was dissolved in EtOAc and neutralised with 20% aqueous K2CO3
5. customPhases were separated
6. washorganic phase was washed with water and brine
7. dry with materialdried over anhydrous Na2SO4
8. filtrationfiltered
9. customevaporated
10. customCrude product was purified by CombiFlash (DCM-MeOH, gradient elution)
11. customevaporated

ORD record

ord-2fbfe3baa9624677b8ac8d1be8cc19ce

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08975254B2