4-Amino-3-methyl-5-nitrobenzonitrile → 3,4-Diamino-5-methylbenzonitrile

To a solution of 4-amino-3-methyl-5-nitro-benzonitrile (3.24 g, 18.3 mmol) in ethanol (80 mL) was added tin chloride dihydrate (8.67 g, 49.75 mmol). The reaction mixture was heated to reflux for 14 h, then cooled to room temperature, and concentrated in vacuum. The residue was diluted with ethyl acetate (100 mL) and treated with triethylamine (20 mL). The resulting slurry was filtered through a pad of celite and the filtercake was rinsed with three-portion ethyl acetate (50 mL). The filtrate was washed with saturated NaHCO3, water, and brine, then dried over Na2SO4 and filtered. After removal of solvent, the residue was purified by flash chromatography on silica gel (30%-50% EtOAc/hexane) to yield the title compound (2.17 g, 81%) as a light yellow solid. 1H NMR (300 MHz, CDCl3) δ 6.94 (1H, s), 6.85 (1H, s), 2.16 (3H, s). LCMS (M+H)+ m/z 148 (t=0.67 min.). Procedure for the Preparation of 5-bromo-3-methyl-benzene-1,2-diamine

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 14 h
3. concentrationconcentrated in vacuum
4. additionThe residue was diluted with ethyl acetate (100 mL)
5. additiontreated with triethylamine (20 mL)
6. filtrationThe resulting slurry was filtered through a pad of celite
7. washthe filtercake was rinsed with three-portion 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 solvent
12. customthe residue was purified by flash chromatography on silica gel (30%-50% EtOAc/hexane)

ORD record

ord-0a9151594efb47f291398ddbab88f8a7

Source dataset

uspto-grants-2007_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07312215B2