Reaction Steps
To a stirred suspension of 4-aminomethyl-2-(2,6-dioxo-piperidin-3-yl)-isoindole-1,3-dione hydrochloride (0.7 g, 2.16 mmol) in CH2Cl2 (60 ml), was added diisopropylethylamine (0.94 mL, 5.4 mmol) and 4-trifluoromethoxybenzoyl chloride (0.6 g, 2.8 mmol). The mixture was then stirred at room temperature overnight. The reaction mixture was quenched with MeOH (1 mL), washed with water (40 mL), 1N HCl (2×40 mL), and brine (40 mL), dried over MgSO4, and concentrated in vacuo. The resulting oil was purified by ISCO silica gel flash chromatography (eluent: 0% MeOH in CH2Cl2 to 5% MeOH in 10 min then stay at this ratio for 15 min) to afford N-[2-(2,6-dioxo-piperidin-3-yl)-1,3-dioxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-4-trifluoromethoxy-benzamide as an off-white solid (0.8 g, 78%): mp, 163-165° C.; HPLC: Waters Symmetry C-18, 3.9×150 mm, 5 micro, 1 mL/min, 240 nm, 40/60 (CH3CN/H2O): tR=7.3 min. (99%); 1H NMR (DMSO-d6): δ 2.07-2.10 (m, 1H), 2.51-2.64 (m, 2H), 2.91-2.92 (m, 1H), 4.96 (d, J=5.7 Hz, 2H), 5.15-5.21 (dd, J=5, 12 Hz, 1H), 7.52 (d, J=8.0 Hz, 2H), 7.74-7.84 (m, 3H), 8.04-8.07 (dd, J=6.8, 1.9 Hz, 2H), 9.28 (t, J=6 Hz, 1H), 11.15 (s, 1H). 13C NMR (DMSO-d6) δ: 21.97, 30.92, 38.44, 118.23, 120.68, 121.64, 121.90, 127.15, 129.30, 129.67, 131.53, 133.01, 133.07, 134.80, 139.03, 150.39, 150.42, 165.39, 166.94, 167.51, 169.81, 172.74. Anal Calcd for C22H16F3N3O6: C, 55.59; H, 3.39; N, 8.84; F, 11.99. Found: C, 55.43; H, 3.00; N, 8.76; F, 11.77.
