反应详情

Selective N-benzylation of the cesium salt of 4-isopropyl-6-hydroxysaccharin (Preparation 19) with benzyl bromide and reaction of the 2-benzyl-4-isopropyl-6-hydroxysaccharin with N,N-diethylthiocarbamyl chloride in DMF using the procedure described above in Preparation 12 affords 2-benzyl-4-isopropyl-6-(N,N-diethylthiocarbamyloxy)saccharin which, on heating, rearranges to 2-benzyl-4-isopropyl-6-(N,N-diethylcarbamyl-thio)saccharin. The latter, on hydrolysis with alkali, affords 2-benzyl-4-isopropyl-6-mercaptosaccharin which on reaction with methyl iodide, and transfer hydrogenolysis affords 4-isopropyl-6-methylthiosaccharin. Oxidation of the latter with one or two molar equivalents of 3-chloroperbenzoic acid affords 4-isopropyl-6-methyl-sulfinylsaccharin and 4-isopropyl-6-methulsulfonyl-saccharin.

1. customdescribed above in Preparation 12