反应详情

A 0.19 g amount of the crude 1-(2-hydroxyethyl)-5,6-dimethylbenzimidazole and 2 ml of 2-cyanoethylphosphoric acid pyridinium salt solution (1 mmol/ml) were dissolved in 20 ml of dry pyridine, and the solution was concentrated to dryness under a reduced pressure. This process was repeated twice more, and further, the dried material was thoroughly dried by a vacuum pump, dissolved in 20 ml of dry pyridine, 1.67 g of dicyclohexylcarbodiimide was added thereto, and the mixture was stored at room temperature for 2 days. After an addition of water to the product, the mixture was concentrated to dryness under a reduced pressure, followed by an addition of 40 ml of an aqueous LiOH solution (0.5 N) to carry out the reaction at 100° C. for 45 minutes. The reaction mixture was filtered to give a filtrate, which was diluted with water, adjusted to a pH of 2.5 to 3, and then the mixture was applied to an ion exchange column (Dowex 50 (hydrogen ion form)). Elution was effected successively with water and 2 N pyridine, and the fractions eluted with the latter were concentrated to dryness under a reduced pressure to give 0.27 g of crude 2-(5,6-dimethylbenzimidazolyl)ethylphosphoric acid.

1. concentrationthe solution was concentrated to dryness under a reduced pressure
2. customfurther, the dried material was thoroughly dried by a vacuum pump
3. dissolutiondissolved in 20 ml of dry pyridine
4. addition1.67 g of dicyclohexylcarbodiimide was added
5. additionAfter an addition of water to the product
6. concentrationthe mixture was concentrated to dryness under a reduced pressure
7. additionfollowed by an addition of 40 ml of an aqueous LiOH solution (0.5 N)
8. customthe reaction at 100° C. for 45 minutes
9. filtrationThe reaction mixture was filtered
10. customto give a filtrate, which
11. washElution
12. washthe fractions eluted with the
13. concentrationlatter were concentrated to dryness under a reduced pressure