N-methyl-2,3-dihydro-1H-indole-5-sulfonamide → N-methyl-1H-indole-5-sulfonamide

Participants

Reaction Steps

N-methyl-indoline-5-sulfonamide (225 mg, 1.06 mmol), as prepared supra, was mixed with 10% palladium on carbon (84 mg) in methanol (8 ml) and these were refluxed for 23 hours. Additional 10% palladium on carbon (100 mg) and methanol (5 ml) were added, and refluxing continued for an additional 23 hours. The cooled reaction mixture was filtered through a Celite® pad, evaporated, and the crude solid redissolved in tetrahydrofuran and again filtered through a Celite® pad. Evaporation of the filtrate gave 211 mg (95%) of N-methyl-1H-indole-5-sulfonamide. This intermediate could also be produced from the reaction of N-methyl-indoline-5-sulfonamide and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in refluxing ethylene glycol monomethyl ether in 35% yield using known procedures. See, e.g. H. Breuer and H. H ohn, Chimie Therapeutique, 6:659 (1973 ).

Provenance & Evidence