2-Sulfonylpyridine derivatives can be industrially produced efficiently by reacting a sulfonyl cyanide derivative with an &agr;,&bgr;-unsaturated carbonyl compound and a 2-{[(2-pyridyl)methyl]thio}-1H-benzimidazole skeleton can be formed in one step in a good yield by reacting this type of the 2-sulfonylpyridine derivative with a 2-methylthio-1H-benzimidazole derivative in the presence of an organolithium compound.