Sodium bis(trimethylsilyl)amide (0.25 mL, 1M in THF, 0.25 mmol) was added to a solution of (R)-3-(1-methyl-2-pyrrolidinylmethyl)-1H-indole (Example 3e, 25.8 mg, 0.12 mmol) in THF (1.5 mL) at -78° C. and the mixture was stirred for 1 h. Phenylsulfonyl chloride (50 μL, 0.39 mmol) was added and the mixture stirred at room temperature for 1 h. prior to quenching with water (6 drops) and silica gel (~1 g). Purification using solid phase extraction tubes (1000 mg silica) eluting with 2M methanolic ammonia in dichloromethane (0-4%) yielded (R)-3-(1-methyl-2-pyrrolidinylmethyl)-1-phenylsulfonylindole (19.7 mg, 46%, HRMS-FAB+ for C20H22N2O2S: calculated MH+ :355.14801; found MH+ :355.14837).
