(4-(5,7-Dioxaspiro[2.5]oct-6-ylmethoxy)pyridin-2-yl)methanol → 2-(((4-(5,7-Dioxaspiro[2.5]oct-6-ylmethoxy)pyridin-2-yl)methyl)sulfinyl)-1h-benzimidazole sodium salt

The same procedure as in the steps (10d) to (10f) of Example 10 was repeated using 2-mercaptobenzimidazole (291 mg, 1.94 mmol) and (4-(5,7-dioxaspiro[2.5]oct-6-ylmethoxy)pyridin-2-yl)methanol (443 mg, 1.76 mmol) to obtain the title compound (300 mg) as a white solid. Note that, in the same process as in the step (10d), 2-mercaptobenzimidazole was added to the reaction mixture and further 2 equivalents of triethylamine was added. The mixture was stirred at room temperature for 2 days.