反应详情

Under an argon gas flow, lithium aluminum hydride (9.70 g, 256 mmol) was suspended in tetrahydrofuran (100 ml); and under an ice cooling, a solution (100 ml) of ethyl 1-methyl-1H-benzimidazole-5-carboxylate (26.1 g, 128 mmol) prepared in the Step 1-1-4 in tetrahydrofuran was slowly added thereto. The mixture was stirred under an ice cooling for one hour. Under an ice cooling, a saturated sodium bicarbonate solution was slowly added to the mixture. The precipitate was removed by filtration, and the residue was concentrated. The concentrate was dissolved in chloroform, and the solution was washed with a saturated sodium bicarbonate solution and then concentrated. The concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1 to 5:1) to give the title compound (11.4 g, 55%) as a light-red powder.

1. additionwas slowly added
2. customThe precipitate was removed by filtration
3. concentrationthe residue was concentrated
4. dissolutionThe concentrate was dissolved in chloroform
5. washthe solution was washed with a saturated sodium bicarbonate solution
6. concentrationconcentrated
7. customThe concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1 to 5:1)