To a solution of 5-bromo-3-(2-pyrrolidinylethyl)-1H-indole (Example 2, 9.10 g, 31 mmol) in tetrahydrofuran (100 mL) cooled to 0° C., were added sodium hydride (12.4 g, 310 mmol) and p-toluenesulfonyl chloride (6.10 g, 32 mmol). The resulting mixture was stirred at room temperature for 3 h, poured into water (200 mL) and extracted into ethyl acetate (200 mL). The organic phase was washed with water (200 mL) and then poured onto a silica gel column which was eluted with ethyl acetate followed by methanol. The title compound was obtained as a yellow syrup (11.7 g, 90%).
