Reaction Steps
A mixture of 2-[(1R)-1-(3-ethoxy-4-methoxyphenyl)-3-hydroxybutyl]-4-(pyrrolylmethyl)isoindoline-1,3-dione (1.26 g, 2.81 mmol), pyridinium chlorochromate (1.21 g, 5.62 mmol), and celite (0.6 g) in methylene chloride (35 mL) was stirred at room temperature for 4 hours. The mixture was filtered through celite and the filtrate was washed with water (30 mL), brine (30 mL). The organic layer of the filtrate was dried over magnesium sulfate. The solvent was removed in vacuo and the residue was purified by chromatography (Silica gel, Hexane:ethyl acetate 6:4) to give 2-[(1R)-1-(3-ethoxy-4-methoxyphenyl)-3-oxobutyl]-4-(pyrrolylmethyl)isoindoline-1,3-dione (0.83 g, 66%) as a white solid: mp 143-145° C.; 1H NMR (CDCl3) δ 7.66 (d, J=7.3 Hz, 1H), 7.53 (t, J=7.7 Hz, 1H), 7.10-7.06 (m, 2H), 6.93 (d, J=7.7 Hz, 1H), 6.82 (d, J=8.0 Hz, 1H), 6.73-6.71 (m, 2H), 6.22-6.21 (m, 2H), 5.78-5.72 (dd, J=5.4, 9.8 Hz, 1H), 3.32-3.23 (dd, J=5.4, 18.0 Hz, 1H), 2.18 (s, 3H), 1.46 (t, J=6.9 Hz, 3H); 13C NMR (CDCl3) δ 205.31, 168.53, 167.83, 149.11, 148.33, 138.31, 134.43, 132.37, 132.04, 131.55, 127.05, 122.34, 121.46, 120.14, 112.59, 111.29, 109.08, 64.39, 55.91, 50.01, 48.53, 44.88, 30.17, 14.72; Anal. Calcd. for C26H26N2O5; C, 69.94; H, 5.87; N, 6.27. Found: C, 70.01; H, 6.01; N, 6.08.