4-Bromo-2-methyl-6-nitroaniline → 5-Bromo-3-methylbenzene-1,2-diamine

To a suspension of 4-bromo-2-methyl-6-nitro-phenylamine (20 g, 0.086 mol) in ethanol (200 mL) was added tin chloride dihydrate (49.2 g, 0.258 mol). The reaction mixture was heated to reflux for 14 h, cooled to room temperature, and concentrated in vacuo. The residue was diluted with ethyl acetate (150 mL) and treated with triethylamine (40 mL). The resulting slurry was filtered through a pad of celite, and the filtercake was rinsed with three portions ethyl acetate (50 mL). The filtrate was washed with saturated NaHCO3, water, and brine, then dried over Na2SO4 and filtered. After removal of the solvent, the residue was purified by flash chromatography on silica gel (30% EtOAc/hexane, then 5% MeOH/CH2Cl2) to yield the title compound (10.26 g, 59%) as a yellow oil. 1H NMR (300 MHz, CDCl3) δ 6.77 (1H, d, J=2.0 Hz), 6.74 (1H, d, J=2.0 Hz), 2.16 (3H, s). LCMS (M+H)+ m/z 201. (t=0.83 min.).

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 14 h
3. concentrationconcentrated in vacuo
4. additionThe residue was diluted with ethyl acetate (150 mL)
5. additiontreated with triethylamine (40 mL)
6. filtrationThe resulting slurry was filtered through a pad of celite
7. washthe filtercake was rinsed with three portions ethyl acetate (50 mL)
8. washThe filtrate was washed with saturated NaHCO3, water, and brine
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. customAfter removal of the solvent
12. customthe residue was purified by flash chromatography on silica gel (30% EtOAc/hexane

ORD record

ord-272c0a8206af4a4e90ea31603bc4498d

Source dataset

uspto-grants-2006_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07081454B2