反应详情

An orange solution consisting of 5-bromo-N-methyl-2-nitroaniline (1-2, 10.5 g, 45.4 mmol) in Acetic acid (200 ml) was treated with Zinc dust (8.92 g, 136 mmol, 3.0 eq), generating a mild exotherm. The cloudy maroon reaction mixture was capped and stirred for 20 min. The reaction was >80% complete, so an additional amount of Zinc dust (1.0 g, 16 mmol, 0.35 eq) was added and the reaction was stirred for 15 min. LC/MS showed complete reduction, so the reaction mixture was filtered through Celite and washed with MeOH. The residual filtrate was concentrated in vacuo, then partitioned between EtOAc (2×300 ml) and saturated aqueous NaHCO3 (350 ml). The combined organic layers were dried over Na2SO4 and concentrated, affording the title compound, 4-bromo-N2-methylbenzene-1,2-diamine (1-3), as a brown solid with >90% purity. LRMS m/z: Calc'd for C7H9BrN2 (M+H) 202.1, found 202.8.

1. customThe cloudy maroon reaction mixture
2. customwas capped
3. stirringthe reaction was stirred for 15 min
4. filtrationso the reaction mixture was filtered through Celite
5. washwashed with MeOH
6. concentrationThe residual filtrate was concentrated in vacuo
7. custompartitioned between EtOAc (2×300 ml) and saturated aqueous NaHCO3 (350 ml)
8. dry with materialThe combined organic layers were dried over Na2SO4
9. concentrationconcentrated