Dissolve indole (2.93 g 0.025 mole) in 10 ml DMF. Cool the solution in an ice-water bath. Add potassium-t-butoxide (3.08 g, 0.0275 mole) and 10 ml DMF. Stir in an ice-bath for 22 minutes. Add iodine (7.61 g, 0.03 mole) and stir in an ice-bath for 12 minutes. Add the second shot of potassium-t-butoxide (3.08 g, 0.0275 mole) and 10 ml DMF. Add the appropriate sulfonyl chloride, 4-(4-fluoro-benzylcarbamoyl)-benzenesulfonyl chloride, (9.01 g, 0.0275 mole) and 10 ml DMF. Stir at ambient temperature for 16 hours. Quench the reaction with 100 ml water, and extract with ethyl acetate (3×150 ml). Wash the organics with sodium metabisulfate (10 g in 100 ml water), water (3×200 ml) and saturated brine (1×200 ml). Concentrate the organics and purify over silica gel using 20% ethyl acetate in heptane to obtain 6.96 g (yield=52.2%) of the desired product as an off-white solid: 1H NMR (DMSO): 9.2 (t, 1H), 8.1 (m, 3H), 8.0 (m, 3H), 7.4 (m, 5H), 7.1 (m, 2H), 4.4 (d, 4H). MS (ES−)=532.91 (M−1).
