Ammonium Hydroxide → 2-Chlorobenzimidazole

Participants

Reaction Steps

2-Hydroxy-1H-benzimidazole (62 g, 0.46 mole) was added to phosphorous oxychloride (200 mL) and the mixture was refluxed for 4.5 hours. The resulting solution was poured over 4 L of ice and the mixture was made strongly basic with ammonium hydroxide. The resulting solid was isolated by filtration, washed with water and dried to provide crude 2-chloro-1H-benzimidazole.

Provenance & Evidence