1-Bromo-4-methoxy-2,3-dinitrobenzene synthesis

Yield:860465-95-8 44%

Reaction Conditions:

with sulfuric acid;nitric acid at 20; for 1 h;Temperature;

Steps:

2.1.a a. 1-Bromo-4-methoxy-2,3-dinitro-benzene

4-Bromo-3-nitroanisole, 97% (10.0 g, 43.1 mmol) was nitrated by dropwise addition of 10 ml of a mixture of nitric acid, fuming 100% (40 ml) and sulfuric acid, 95-98% (6 ml). The mixture was stirred for 1 h at RT. The reaction mixture was poured onto ice water and extracted three times with ethyl acetate. The combined organic layers are washed with water and brine, dried over Na2S0₄, filtered and concentrated to dryness. The crude material was purified by flash chromatography (ethyl acetate/cyclohexane) to yield in 5.30 g (44%) of the title compound as a yellow solid. HPLC/MS (purity) 100%. Rt 2.65 min (method A). [M+H]+ 276.8, 278.9.

References:

WO2019/38215,2019,A1 Location in patent:Page/Page column 189-190; 194-195