20034-00-8

GENERAL METHOD: 4-nitrophthalamide (10 mmol) was mixed with ethanoic acid (2.28 g, 30 mmol) in a reaction flask and concentrated phosphoric acid (20 mL) was added as a catalyst. The reaction mixture was heated to 130 °C and kept at reflux for 3 hours. Upon completion of the reaction, the reaction was quenched with 20% sodium hydroxide solution. The resulting 5-nitro-1H-benzimidazole-2-methanol solid product was separated and collected by filtration.

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