反应详情

By the method of part D of Example 45 in two successive preparations 2-benzyl-4-ethoxy-7-(t-butoxycarbonylmethoxy) saccharin (0.5 g, 6.5 g) was debenzylated with ammonium formate (0.25 g, 3.66 g) and palladium on carbon (10%, 0.25 g, 2 g) in methanol affording 4-ethoxy-7-(t-butoxycarbonylmethoxy)saccharin ammonium salt (0.44 g, 5.63 g), phenylthiomethylation of which with chloromethyl phenyl sulfide (0.2 g, 2.38 g) in dimethylformamide and purification of the combined products (0.46 g, 6.42 g) by column chromatography on silica gel using dichloromethane and dichloromethane-acetone (98:2) as eluants afforded 2-phenylthiomethyl-4-ethoxy-7-(t-butoxycarbonylmethoxy)saccharin, 1.92 g, 40% yield.