反应详情

3.9 g of methyl 2-hydroxy-1H-benzimidazole-5-carboxylate and 50 ml of phosphorus oxychloride are stirred at 10° C. for 6 hours. The resulting thick slurry is, after cooling, stirred cautiously into 500 ml of ice-water, and the solid is filtered off with suction after one hour, washed with water and dried under reduced pressure.

1. temperatureafter cooling
2. filtrationthe solid is filtered off with suction after one hour
3. washwashed with water
4. customdried under reduced pressure