A stirred solution of methyl ester (B) (0.5 g) in methylene chloride (16 ml) was cooled to 0° C. and treated with triethylamine (0.34 ml) followed by 2-ethylhexanoyl chloride (0.31 ml). The resulting solution was stirred at 0° C. for 15 minutes and then at room temperature for 30 minutes. The mixture was diluted with ethyl acetate and poured into cold water. The organic layer was washed sequentially with 10% v/v hydrochloric acid, water, and brine; dried (MgSO4) and evaporated. The residue was purified by flash chromatography on a 4×18 cm silica gel column using 35:65 v/v ethyl acetate:hexane as the eluent to give methyl 4-[6-(2-ethylhexanamido)indol-1-ylmethyl]-3-methoxybenzoate (C) (0.7 g; 99%) as a white solid; partial NMR: 0.9(t, 6H, 2CH3), 1.5(m, 9H).
