To a solution of 1-[1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propan-1-ol (300 mg, 0.797 mmol) in N,N-dimethylformamide (3.0 mL) was added sodium hydride (60% in oil, 35.0 mg, 0.877 mmol), and the mixture was stirred at room temperature for 10 min. To the mixture was added 2-bromoethyl methyl ether (166 mg, 1.19 mmol), and the mixture was stirred at room temperature for 3 hr. The mixture was diluted with water, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound as a colorless amorphous (218 mg, 0.502 mmol, 63%).
