Acetic Acid → 4-bromo-2-methyl-6-nitro-1H-benzo[d]imidazole

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Reaction Steps

A mixture of 3-bromo-5-nitrobenzene-1,2-diamine (90 g, 389 mmol) in acetic acid (800 mL) was stirred under reflux for 18 h. The solvent was removed in vacuo. The residue was purified by silica gel column chromatography (petroleum ether/ethyl acetate=1/1) to give the product (56 g, 56.6%) as a brown solid; LC/MS: MS (ES+) m/e 256 [M+H]+; 1H NMR (300 MHz, DMSO-d6) δ ppm 2.60 (s, 3H), 8.20 (d, J=1.8 Hz, 3H), 8.34 (d, J=1.8 Hz, 2H), 13.25 (s, br, 1H).

Provenance & Evidence