4-Nitro-1,2-phenylenediamine → 2-[2-(3,4-Dimethoxy-phenyl)-vinyl]-5-nitro-1H-benzimidazole

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Reaction Steps

A mixture of 4-nitro-1,2-phenylenediamine (1.2 g; 8 mmol) and methyl-(3,4-dimethoxy)-cinnamoimidate hydrochloride (2.0 g; 8 mmol) in methanol (70 mL) was refluxed for 18 hours. Solution was concentrated to dryness. The residue was recrystallized from MeOH to obtain 603 mg (23% yield) of the title compound as a yellow solid, m.p. 223-225° C. Anal. Calcd. for C17H15N3O4: C, 62.76, H, 4.65; N, 12.92. Found: C, 62.67; H, 4.62; N, 13.05. Mass spectrum: (EI; M+) m/z 325. 1H-NMR (DMSO-d6; 400 MHz) δ13.2(broad s, 1H), 8.4 (broad s, 1H), 8.1(dd, 1H), 7.74 (s, 1H), 7.62-7.72 (m, 1H), 7.35 (d 1H), 7.19-7.23 (dd, 1H), 7.17 (s, 1H), 7.0 (d,1H),3.85 (s, 3H), 3.8 ppm (s, 3H).

Provenance & Evidence