反应详情

To a solution of 1-[9-chloro-1-(6-methoxy-2-methylpyridin-3-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propan-1-ol (200.0 mg, 0.517 mmol) in pyridine (1.0 mL) was added acetic anhydride (0.5 mL) at 0° C. The reaction mixture was stirred at room temperature for 5.5 hrs. The mixture was concentrated. The residue was neutralized with aqueous saturated sodium hydrogen carbonate and extracted with ethyl acetate (×3). The combined organic layer was washed with brine (×1), dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 0-50% ethyl acetate/n-hexane gradient mixture. The residue was recrystallized from ethanol/n-hexane to give the title compound as a colorless powder (148.4 mg, 0.346 mmol, 67%).

1. concentrationThe mixture was concentrated
2. extractionextracted with ethyl acetate (×3)
3. washThe combined organic layer was washed with brine (×1)
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was purified by silica gel column chromatography
8. washeluting with a 0-50% ethyl acetate/n-hexane gradient mixture
9. customThe residue was recrystallized from ethanol/n-hexane