Reaction Steps
Triethylamine (0.7 g, 7.4 mmol) was added to a stirred suspension of 3-(4-aminomethyl-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione hydrochloride (0.7 g, 2.1 mmol) and picolinoyl chloride hydrchloride (0.5 g, 2.5 mmol) in THF (30 mL) at 5-10° C. After stirring at 5° C. for 10 minutes, the mixture was stirred at room temperature overnight. The mixture was concentrated, and the residue was stirred with H2O (30 mL). The mixture was filtered, and the solid was slurried with hot methanol (15 mL) to give pyridine-2-carboxylic acid [2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-amide (0.6 g, 78%): mp 254-256° C.; 1H NMR (DMSO-d6) δ 2.01-2.06 (m, 1H), 2.32-2.66 (m, 2H), 2.86-3.01 (m, 1H), 4.43-4.65 (m, 4H, 2CH2), 5.12-5.19 (dd, J=4.7 and 13.0 Hz, 1H, CH), 7.45-7.64 (m, 4H, Ar), 7.97-8.07 (m, 2H, Ar), 8.65 (d, J=4.2 Hz, 1H, Ar), 9.51 (t, J=5.8 Hz, 1H, NH), 11.03 (s, 1H, NH); 13C NMR (DMSO-d6) δ 22.59, 31.17, 46.30, 51.57, 121.63, 122.02, 126.60, 128.28, 130.77, 131.58, 134.73, 137.79, 140.08, 148.44, 149.80, 164.16, 168.06, 170.99, 172.82; Anal. calcd. for C20H18N4O4: C, 63.49; H, 4.79; N, 14.81. Found: C, 63.32; H, 4.66; N, 14.80.