Ammonium Chloride → 4-[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]hexan-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-[9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]-N-methoxy-N-methylpentanamide (148.6 mg, 0.30 mmol) in tetrahydrofuran (10 mL) was added methylmagnesium bromide (3.0 M in diethyl ether, 0.3 mL, 0.9 mmol) at 0° C. The reaction mixture was stirred at 0° C. for 2 hr and at room temperature for 1 hr. Methylmagnesium bromide (3.0 M in diethyl ether, 0.3 mL, 0.9 mmol) was added to the reaction mixture at room temperature. After the mixture was stirred at room temperature for 2 hr, aqueous ammonium chloride was added to the reaction mixture. 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 20-60% ethyl acetate/n-hexane gradient mixture to give the title compound (96.0 mg, 0.213 mmol, 71%) as colorless crystals.

Provenance & Evidence