Sodium Hydroxide → 3-Bromobenzene-1,2-diamine

To a stirring slurry of tin(II) chloride dihyrate (11.8 g, 52.3 mmol) in conc. hydrochloric acid (55 mL) was added 2-bromo-6-nitroaniline (2.84 g, 13.1 mmol), and the resulting mixture was stirred at room temperature for 5 minutes—an exotherm was observed. The mixture was then stirred at reflux for 30 minutes. After cooling to room temperature, the slurry was poured onto crushed ice (200 mL), and the pH was adjusted to 14 by the addition of sodium hydroxide pellets. The resulting mixture was washed with diethyl ether (5×100 mL), then the combined organic layers were dried (MgSO4) and concentrated in vacuo. The crude product was purified by chromatography on a Biotage SP1 apparatus, on a 40S silica gel column, eluting with 5% to 50% ethyl acetate in dichloromethane, yielding the product as a yellow-brown oil, which solidified upon standing (2.02 g, 87%) 1H NMR (400 MHz, CDCl3): δ 6.97 (1H, dd, J=1.4, 8.0 Hz), 6.64 (1H, dd, J=1.4, 7.8 Hz), 6.56 (1H, t, J=7.9 Hz), 3.61 (3H, s); m/z (ES+) 187, 189 [MH+].

1. stirringThe mixture was then stirred
2. temperatureat reflux for 30 minutes
3. temperatureAfter cooling to room temperature
4. additionthe slurry was poured
5. washThe resulting mixture was washed with diethyl ether (5×100 mL)
6. dry with materialthe combined organic layers were dried (MgSO4)
7. concentrationconcentrated in vacuo
8. customThe crude product was purified by chromatography on a Biotage SP1 apparatus, on a 40S silica gel column
9. washeluting with 5% to 50% ethyl acetate in dichloromethane

ORD record

ord-bef2e7c9f0724ee7917ebbd27a784024

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07592456B2