反应详情

Methyl 2-oxo-2,3-dihydro-1H-benzimidazole-6-carboxylate (43 g, 0.22 mol) was charged into phosphorus oxychloride (286 ml). Dry hydrogen chloride was bubbled through the boiling reaction mass for 12 hours. After cooling a reaction mass was poured into a mixture of ice and water (2 kg). Precipitate was filtered out. Filtrate was diluted with water (1.25 1) and ammonia solution (˜800 ml), after that pH was adjusted to 5.6 with ammonia solution. Precipitate was filtered and rinsed with water. Yield was 39.5 g (84%).

1. customDry hydrogen chloride was bubbled through the boiling reaction mass for 12 hours
2. temperatureAfter cooling a reaction mass
3. additionwas poured into a mixture of ice and water (2 kg)
4. filtrationPrecipitate was filtered out
5. additionFiltrate was diluted with water (1.25 1) and ammonia solution (˜800 ml)
6. filtrationPrecipitate was filtered
7. washrinsed with water