Thionyl Chloride → 2-[[(4-Methoxy-3-methyl-2-pyridinyl)methyl]thio]-1H-benzimidazole

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Reaction Steps

5.7 g of 2-acetoxymethyl-3-methyl-4-methoxy-pyridine was dissolved in chloroform, and 18 g (4 eq.) of thionyl chloride was added. The mixture was heated to reflux for one hour and then concentrated, and a residue resulting therefrom was dissolved in methanol. The solution was added in advance to 5.3 g (1 eq.) of 2-mercaptobenzimidazole, 45 mL of a 28% sodium methoxide solution, and 100 mL of methanol, and the mixture was heated to reflux for one hour. Methanol was distilled off, and ice and ethyl acetate were added to the residue, to wash the residue by suspending. Produced crystals were collected by filtration, and then were washed by suspending in water, to obtain 7.1 g of colorless crystals. Total yield 20.9% (purity by HPLC: 98.2%).

Provenance & Evidence