Sulfuric Acid → 9-Chloro-1-(2,4-dichlorophenyl)-6-[1-(1-methylethoxy)propyl]-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole

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Reaction Conditions

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 (151.3 mg, 0.368 mmol) in 2-propanol (10.0 mL) was added sulfuric acid (0.45 mL) at 0° C. The reaction mixture was stirred at 100° C. for 16 hrs. The mixture was poured into aqueous saturated sodium hydrogen carbonate and concentrated. The residue was 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 0-30% ethyl acetate/n-hexane gradient mixture to give the title compound as a colorless amorphous (84.7 mg, 0.187 mmol, 51%).

Provenance & Evidence