4-Hydroxy-2-methyl-3(2H)-isothiazolone-1,1-dioxide as protecting group of 4-(N-methylaminosulfonyl)methylphenylhydrazine during Fischer indole synthesis
Protection of the benzylic position of 4-methylaminosulfonylmethylphenyl hydrazine 6 with a 4-hydroxy-2-methyl-3(2H)-isothiazolone-1,1-dioxide group allowed the preparation of indole 3 without formation of side-product.