Acetic Anhydride → 1-[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propyl acetate

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Reaction Steps

To a solution of 1-[9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propan-1-ol (139.8 mg, 0.340 mmol) in pyridine (0.8 mL) was added acetic anhydride (0.5 mL) at 0° C. The reaction mixture was stirred at room temperature for 16 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 0-40% ethyl acetate/n-hexane gradient mixture. The residue was recrystallized from diisopropyl ether/n-hexane to give the title compound as a colorless powder (123.2 mg, 0.272 mmol, 80%).

Provenance & Evidence