反应详情

To a solution of ethyl 3-[9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]pentanoate (100 mg, 0.208 mmol) in tetrahydrofuran (10 mL) was added lithium tetrahydroborate (23 mg, 1.06 mmol) at 0° C. The mixture was stirred at room temperature for 18 hr. Then the mixture was warmed to. 40° C. and stirred at 40° C. for 5 hr. Aqueous ammonium chloride was added to the reaction mixture at 0° C. and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with a 50-100% ethyl acetate/n-hexane gradient mixture and recrystallization from ethyl acetate/n-hexane to give the title compound (41.7 mg, 0.095 mmol, 46%) as colorless crystals.

1. temperatureThen the mixture was warmed to
2. stirring40° C. and stirred at 40° C. for 5 hr
3. extractionthe mixture was extracted with ethyl acetate
4. washThe organic layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash chromatography on silica gel eluting with a 50-100% ethyl acetate/n-hexane gradient mixture and recrystallization from ethyl acetate/n-hexane