反应详情

Under ice cooling, thionyl chloride (2.30 ml) was added dropwise to methanol (50 ml). Then, 5-benzimidazolecarboxylic acid (5.00 g) was added, followed by heating under reflux for 5 hours. The reaction mixture was distilled under reduced pressure. The residue was pulverized in diethyl ether, followed by collection through filtration, whereby colorless crystals (6.36 g, 97%) was obtained.

1. temperatureby heating
2. temperatureunder reflux for 5 hours
3. distillationThe reaction mixture was distilled under reduced pressure
4. filtrationfollowed by collection through filtration