Reaction Steps
A stirred solution 1-(3-ethoxy-4-methoxyphenyl)-2-methylsulfonylethylamine (640 mg, 2.34 mmol) and 3-nitrophthalic anhydride (460 mg, 2.34 mmol) in acetic acid (10 mL) was heated at reflux for 15 h. The solvent was removed in vacuo to yield an oil. Chromatography of the resulting oil yielded 2-[1-(3-ethoxy-4-methoxyphenyl)-2-methylsulfonylethyl]-4-nitroisoindoline-1,3-dione as a yellow solid (850 mg, 81% yield): mp, 110.0-114.0° C.; 1H NMR (CDCl3); δ 1.47 (t, J=7.0 Hz, 3H, CH3), 2.90 (s, 3H, CH3), 3.71 (dd, J=4.3, 14.4 Hz, 1H, CHH), 3.85 (s, 3H, CH3), 4.10 (q, J=7.0 Hz, 2H, CH2), 4.58 (dd, J=10.7, 14.4 Hz, 1H, CHH), 5.93 (dd, J=4.2, 10.7 Hz, 1H, NCH), 6.84 (d, J=8.8 Hz, 1H, Ar), 7.11-7.15 (m, 2H, Ar), 7.89 (t, J=7.8 Hz, 1H, Ar), 8.08-8.13 (m, 2H, Ar); 13C NMR (CDCl3) δ 14.67, 41.56, 49.19, 53.97, 55.96, 64.56, 111.52, 112.51, 120.62, 123.44, 127.35, 128.65, 128.84, 133.73, 135.48, 145.24, 148.68, 149.92, 162.53, 165.33; Anal Calcd for C20H20NO8S: C, 53.57; H, 4.50; N, 6.23. Found: C, 53.54; H, 4.28; N, 6.32