Potassium carbonate (207 mg), trimethylboroxin (175 μL) and bis(diphenylphosphino)ferrocene dichloropalladium (II) (40.8 mg) were added to a solution of tert-butyl {[4-bromo-1-(3-methoxypropyl)-1H-indol-3-yl]methyl}cyclopropylcarbamate (218 mg) in 1,4-dioxane (14.5 ml) and the mixture was stirred at 110° C. under argon atmosphere for 4 hours. After being cooled to room temperature, the reaction mixture was diluted with water and the mixture was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium bicarbonate and saturated brine successively, dried over magnesium sulfate and concentrated in vacuo. The resulted residue was purified with a silica gel column chromatography (eluting solvent: n-hexane to n-hexane/ethyl acetate=1/1 to 1/4) to give tert-butyl cyclopropyl{[1-(3-methoxypropyl)-4-methyl-1H-indol-3-yl]methyl}carbamate (180 mg) as a yellow oil.
