Methyl iodide → 1H-Benzimidazole, 5,6-dichloro-1-methyl-2-(methylthio)-

Participants

Reaction Steps

5,6-dichloro-2-mercaptobenzimidazole (8.76 g, 0.04 mol) in 50 ml 95% ethanol was treated with 10 ml of 45% aqueous potassium hydroxide to give a solution. Iodomethane (7 ml, 0.096 mol) was added. The reaction mixture was refluxed for two hours. Cooling overnight yielded precipitant, which was filtered, water-washed, and dried to yield 5.61 g, mp 115° C. The reaction filtrate was rotary evaporated and the residue reslurried in water. After filtration and drying, an additional 3.52 g was obtained, mp 110° C. NMR analysis indicated the presence of some 5,6-DiChloro-2-(methylthio)benzimidazole as an impurity.

Provenance & Evidence