反应详情

A 1.46 g amount of 5,6-dimethylbenzimidazole was dissolved in 50 ml of dry N,N-dimethylformamide, 0.96 g of NaH was added to the solution, and the mixture was stirred in an ice-water bath for 30 minutes. Then to the mixture was added dropwise 5 ml of ethylene chloride, the mixture was stirred at room temperature for 15 hours, and the reaction was further carried out for 24 hours while adding 0.78 g of NaH. The reaction was stopped by an addition of 50 ml of water, and the obtained reaction mixture was washed with n-hexane, diluted with water, adjusted to a pH of 2.5 with HCl, and then applied to an ion exchange column (Dowex 50 (hydrogen ion form)). An elution was effected successively with water, 30% ethanol, and ammoniacal 30% ethanol, and the fractions eluted with ammoniacal 30% ethanol were concentrated to dryness under a reduced pressure to give crude 1-(2-hydroxy-ethyl)-5,6-dimethylbenzimidazole. The conversion to this compound from 5,6-dimethylbenzimidazole was found to be 75% by an assay according to thin layer chromatography.

1. stirringthe mixture was stirred at room temperature for 15 hours
2. waitthe reaction was further carried out for 24 hours
3. customthe obtained reaction mixture
4. washwas washed with n-hexane
5. additiondiluted with water
6. washAn elution
7. washthe fractions eluted with ammoniacal 30% ethanol
8. concentrationwere concentrated to dryness under a reduced pressure