In a dry reaction vessel, ethyl 2-[3-(4-aminobenzyl)-2-ethyl-1H-indol-1-yl]acetate (288 mg, 0.86 mmol) was added, and dissolved in 7 mL dichloromethane. Triethylamine (0.36 mL, 2.59 mmol) was added, in an ice bath a dichloromethane solution 2 mL dissolving 2-naphthoyl chloride (163 mg, 0.86 mmol) was added slowly. After completion of dropwise addition, it was reacted in an ice bath for 1 h, and stirred at room temperature overnight. Water was added into the system, extracted with dichloromethane, rotate evaporated to dryness to obtain a crude. It was washed again with a small amount of acetonitrile to obtain the yellow product 340 mg, at a yield of 80.2%.
