m-Chloroperbenzoic acid → tert-butyl (4-{3-chloro-2-[(2,5-dioxo-1-pyrrolidinyl)methyl]-7-oxido-5,8-dihydro-6H-thiopyrano[4',3':4,5]thieno(2,3-b]pyridin-4-yl}phenoxy)-acetate

Participants

Reaction Steps

To a solution of the compound obtained in Example 112 (2.7 g) in methylene chloride (50 ml) was added m-chloroperbenzoic acid (70%, 1.2 g) under ice-cooling and the mixture was stirred at room temperature for 1 hour. The reaction mixture was washed with an aqueous saturated sodium bicarbonate solution and then water and dried (MgSO4) and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain tert-butyl (4-{3-chloro-2-[(2,5-dioxo-1-pyrrolidinyl)methyl]-7-oxido-5,8-dihydro-6H-thiopyrano[4′,3′:4,5]thieno(2,3-b]pyridin-4-yl}phenoxy)-acetate from the fraction eluted with ethyl acetate. It was recrystallized from ethyl acetate-hexane (2.2 g, 79%). Colorless prisms. Melting point 175-176° C.

Provenance & Evidence