3-Pyridinecarboxaldehyde → 5-bromo-1-methyl-2-(pyridin-3-yl)-1H-benzimidazole-6-carbonitrile

Participants

Reaction Steps

To solution of 4-amino-2-bromo-5-(methylamino)benzonitrile (0.2 g, 0.0008 mol) and nicotinaldehyde (0.094 g, 0.0008 mol) in DMF (5 ml) and H2O (2 ml) was added OXONE® monopersulphate (0.43 g, 0.0007 mol). Reaction mass was stirred at room temperature for 3 h. The reaction mixture was quenched with 10% K2CO3 solution to PH˜8-10 and extracted with EtOAc (3×20 ml). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated under vacuum to afford the crude compound, which was purified by column chromatography to obtain title compound 5-bromo-1-methyl-2-(pyridin-3-yl)-1H-benzimidazole-6-carbonitrile. (3971H NMR (400 MHz, DMSO-d6), δ: 9.08 (s, 1H), 8.80-8.79 (d, J=4 Hz, 1H), 8.53 (s, 1H), 8.34-8.32 (d, J=7.2 Hz, 1H), 8.23 (s, 1H), 7.67-7.63 (m, 1H), 3.96 (s, 3H). MS (M+1): 313.12, Purity 93.84%.

Provenance & Evidence