反应详情

m-Chloroperbenzoic acid (1.06 g) in dichloromethane (50 ml) was added dropwise to a stirred solution of 5-methoxy-2-(4-morpholino-3-fluoro-2-pyridylmethylthio)-(1H)-benzimidazole (2.31 g) in dichloromethane (50 ml) at -30° to -35°. After 0.5 hour at -30° a further addition of m-chloroperbenzoic acid (0.106 g) in dichloromethane (15 ml) was made and the mixture stirred for a further 20 minutes at -30°. Ammonia gas was then passed through the solution and the precipitated benzoate salts filtered off. The filtrate was evaporated to dryness and the residue crystallised from ethyl acetate to yield 2-(4-morpholino-3-fluoro-2-pyridylmethylsulphinyl)-5-methoxy-(1H)-benzimidazole (1.75 g) m.p. 142°-46°

1. filtrationthe precipitated benzoate salts filtered off
2. customThe filtrate was evaporated to dryness
3. customthe residue crystallised from ethyl acetate