Title compound 398 (0.304 g, 1.54 mmol) was dissolved in acetonitrile (5.0 mL) and the ethyl 7-iodoheptanoate (0.613 g, 2.16 mmol) and the potassium carbonate (0.639 g, 4.62 mmol) were added. The reaction mixture was stirred at 70° C. for 60 hours. The mixture was cooled down and diluted with ethyl acetate. The organic phase was washed with water and brine, dried over sodium sulfate, filtered and evaporated. The residue was purified by flash chromatography with 10% ethyl acetate in hexanes to afford title compound 399 (201 mg, 37%). MS (m/z): 354.2 (M+H).
