Hydrogen Peroxide → Lansoprazole

Participants

Reaction Steps

Vanadium(IV) acetylacetonate (40 mg) was dissolved in ethanol (150 ml), to which 2-[[3-methyl-4-(2,2,2-trifluoroethoxy)pyrid-2-yl]methylthio]benzimidazole (monohydrate) (20.0 g) was added and then 35% aqueous solution of hydrogen peroxide (6.14 g) was added dropwise at 20°-25° C., and the mixture was allowed to react at 20°-25° C. for about 5 hours. After completion of the reaction, a solution of sodium thiosulfate (2.7 g/16 ml) was added to the reaction mixture and stirred vigorously for about 10 minutes. The crystals were collected by filtration and washed with an ice-cooled mixture of ethanol-water (8:2). The crystals thus obtained were treated with a mixture of ethanol-water (9:1, 90 ml), heated (60°-70° C.), and stirred so that the crystals were dissolved, then the insoluble matters were removed by hot filtration. The filtrate was ice-cooled for crystallization and the crystals were collected by filtration, washed with ice-cooled ethanol-water mixture (8:2) and dried in vacuo, to give white needles of 2-[[3-methyl-4-(2,2,2-trifluoroethoxy)pyrid-2-yl]methylsulfinyl]benzimidazole (18.1 g). (yield: 91.0%).

Provenance & Evidence