3-(2-Nitro-2-methylpropyl)-7-nitroindole (1.89 g, 7.2 mmol) is dissolved in ethyl acetate (75 mL) and 10% Pd/C is added (750 mg). The mixture is stirred under a balloon of nitrogen for 2–3 hours. The mixture is filtered to remove the Pd/C, and the filtrate is evaporated to give a crude oil. This crude 3-(2-nitro-2-methylpropyl)-7-aminoindole is immediately dissolved in pyridine (100 mL) and the solution is cooled with an ice bath to 0° C. Benzenesulfonyl chloride is added slowly, and the mixture is stirred for 5 minutes at this temperature before removing the ice bath. The reaction mixture is stirred overnight before being quenched by addition of IN HCl and ethyl acetate. The aqueous layer is extracted with ethyl acetate several times and the combined organic extracts are washed twice with brine and dried over Na2SO4 to give a crude oil. The crude material is purified by flash chromatography (25% ethyl acetate/hexanes) to provide 1.9 g of 3-(2-nitro-2-methylpropyl)-7-benzenesulfonamidyl-indole (71%).
