Dimethyl Sulfate → Butyrophenone, 4'-fluoro-4-(4-(2-methylthiobenzimidazol-1-yl)piperidino)-

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Reaction Steps

15.9 g of 1-[1-(3-(4-fluorobenzoyl)propyl)-4-piperidyl]-2-mercaptobenzimidazole and 3.2 g of sodium hydroxide were dissolved in a mixture of 24 ml of water and 200 ml of methanol. To the solution, 7.06 g of dimethyl sulfate was added through 4 hours at room temperature (i.e., about 20°-30°C) and then the solution was stirred for an additional 20 minutes. After the reaction, the solution was concentrated and a diluted sodium hydroxide solution was added thereto, followed by extracting with chloroform. The chloroform solution was washed with water, dried and concentrated. The residue was recrystallized from ethanol to give colorless crystals of 1-[1-(3-(4-fluorobenzoyl)-propyl)-4-piperidyl]-2-methylmercaptobenzimidazole having a melting point of 98° to 98.5°C.

Provenance & Evidence