To a solution of Example 1 (0.2 g, 0.66 mmol) in DMF (5 mL) was added triethylamine (0.16 mL, 1.14 mmol) and methyl 3-bromopropionate (0.07 mL, 0.64 mmol). The resulting slurry was stirred at ambient temperature overnight. The solvent was removed under reduced pressure and the crude residue was extracted into ethyl acetate. The organic portion was washed with water, washed with brine, dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The crude product was purified by silica gel flash chromatography using hexane/EtOAc (gradient system) to give the title compound (0.03 g, 13%); 1H NMR (400 MHz, CDCl3); δ 1.68-1.80 (m, 3H), 1.93-2.04 (m, 1H), 2.29 (q, J=8.4 Hz, 1H), 2.53 (t, J=7.2 Hz, 2H), 2.70 (m, 1H), 2.87 (m, 1H), 3.13 (m, 1H), 3.24 (m, 1H), 3.66 (s, 3H), 3.75 (m, 1H), 3.92 (s, 2H), 3.93 (m, 1H), 6.82 (d, J=8.8 Hz, 2H), 7.08 (d, J=8.4 Hz, 2H), 7.16-7.20 (m, 3H), 7.27 (m, 2H); MS (m/z) 354.2 (M+1); LC (100.0%).
