m-Chloroperbenzoic acid → 2-(((3-methyl-4-(1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy)pyridin-2-yl)methyl)sulfinyl)-1H-benzimidazole

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Reaction Steps

To a toluene (30 ml)-methanol (3 ml) solution of the 2-(((3-methyl-4-(1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy)pyridin-2-yl)methyl)thio)-1H-benzimidazole (974 mg, 2.21 mmol) obtained in the step (10d), a toluene (1 ml)-methanol (1 ml) solution of 3-chloroperbenzoic acid (528 mg, 1.99 mmol as the content was regarded as 65%) was added dropwise at −65° C. for 5 minutes in a nitrogen atmosphere. The mixture was stirred for 55 minutes in the same conditions. To the reaction mixture, a saturated aqueous solution of sodium hydrogen carbonate was added. The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography (NH silica gel: 20 g, elution solvent: dichloromethane, dichloromethane/methanol=10/1). The fractions containing the title compound were collected with ethyl acetate and concentrated. After diethyl ether was added to the residue, the solvent was distilled off to obtain the title compound (725 mg, yield: 71.7%) as a pale grayish solid.

Provenance & Evidence