Reaction Steps
A mixture of N-{2-[1-(3-ethoxy-4-methoxyphenyl)-3-hydroxybutyl]-1,3-dioxoisoindolin-4-yl}acetamide (1.2 g, 2.81 mmol), pyridium chlorochromate (1.21 g, 5.63 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 celite washed with methylene chloride. The filtrate was washed with water, brine, dried, and concentrated. The residue was purified by chromatography (silica gel, methylene chloride:ethyl acetate 9:1) to yield N-{2-[1-(3-ethoxy-4-methoxyphenyl)-3-oxobutyl]-1,3-dioxoisoindolin-4-yl}acetamide as a white solid (0.9 g, 76%); mp 128-129° C.; 1H NMR (CDCl3) δ 9.52 (s, 1H), 8.71 (d, J=8.4 Hz, 1H), 7.62 (t, J=7.5 Hz, 1H), 7.46 (d, J=7.2 Hz, 1H), 7.06-7.03 (m, 2H), 6.82 (d, J=8.9 Hz, 1H), 5.73-5.07 (dd, J=5.2 and 10.0 Hz, 1H), 4.11 (q, J=7.0 Hz, 2H), 4.04-3.93 (dd, J=10.0 and 18.0 Hz, 1H), 3.83 (s, 3H), 3.28-3.19 (dd, J=5.2 and 18.0 Hz, 1H), 2.26 (s, 3H), 2.18 (s, 3H), 1.46 (t, J=7.1 Hz, 3H); 13C NMR (CDCl3) δ 205.18, 170.62, 169.17, 167.10, 149.21, 148.40, 137.38, 135.81, 131.34, 131.24, 124.69, 120.02, 117.91, 115.30, 112.57, 111.37, 64.44, 55.93, 49.96, 44.82, 30.14, 24.93, 14.73; Anal. Calcd. For C23H24N2O6: C, 65.08; H, 5.70; N, 6.60. Found: C, 65.11; H, 5.64; N, 6.50.
