Hydrochloric Acid → 5-Bromopyridine-2,3-diamine

A mixture of 2-amino-5-bromo-3-nitropyridine (62.2 g, 285 mmol), iron powder (171 g, 3.06 mol), concentrated hydrochloric acid (2.85 ml), water (60 ml) and ethanol (230 ml) was refluxed for 2 h, filtered whilst warm, the solids washed twice with ethanol (2×150 ml) and the combined ethanol solutions were evaporated to dryness. The crude solid was recrystallized from water, using decolourising charcoal, filtered whilst warm, the solids washed twice with warm ethanol (2×100 ml), the ethanol evaporated off and the precipitate was filtered off, washed with water (3×75 ml) and dried to afford the title compound (27 g, 50%).

1. temperaturewas refluxed for 2 h
2. filtrationfiltered
3. temperaturewhilst warm
4. washthe solids washed twice with ethanol (2×150 ml)
5. customthe combined ethanol solutions were evaporated to dryness
6. customThe crude solid was recrystallized from water
7. filtrationfiltered
8. temperaturewhilst warm
9. washthe solids washed twice with warm ethanol (2×100 ml)
10. customthe ethanol evaporated off
11. filtrationthe precipitate was filtered off
12. washwashed with water (3×75 ml)
13. customdried

ORD record

ord-0b2d1ebe123f442d854a307301173c41

Source dataset

uspto-grants-2008_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07410966B2