Dimethyl Sulfate → 2-(2-Bromophenyl)-1-methyl-1H-benzimidazole

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Reaction Steps

To a flask were added 3.3 g 2-(2-bromophenyl)-1H-benzimidazole and 100 ml tetrahydrofuran and the mixture was cooled to 10 C under nitrogen. 0.63 g Sodium hydride were added in portions and the reaction mixture was stirred for 20 minutes. 2.0 g Dimethylsulfate were added and the mixture was heated to 22 C for 30 minutes. The mixture was quenched slowly with 100 ml water, extracted with ethyl acetate and then extracted into a 1 M hydrochloric acid solution. The solution was washed with ethyl acetate and then basified with 3M sodium hydroxide. Following extraction with ethyl acetate and solvent removal, the solid was dissolved in a hot mixture of 20 ml hexane with 4 ml 2-propanol. After cooling to 5 C, the product was filtered, washed with hexane and dried giving 2.9 g of a white solid.

Provenance & Evidence