3-(5-aminomethyl-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione methanesulfonate (1.11 g, 3.0 mmol) and 1,1′-Carbonyldiimidazole (535 mg, 3.3 mmol) were suspended in dry DMF (20 mL) and the mixture was stirred at rt for 24 h. While stirring, a portion of the reaction mixture (6.7 mL, ˜1 mmol) was transferred to a vial containing 3-chloro-4-(2-(2-methoxyethoxy)ethoxy)aniline hydrochloride (310 mg, 1.1 mmol). The resulting mixture was stirred at rt overnight and the reaction progress was monitored by LCMS. After 48 h, additional 3-chloro-4-(2-(2-methoxyethoxy)ethoxy)aniline hydrochloride (56 mg, 0.2 mmol) was transferred to the reaction mixture and stirring continued for another 24 h. The reaction mixture was acidified with 1N HCl and water was added with stirring until a precipitate formed. The solid was collected by filtration, suction dried, then dissolved in DMF and purified using C-18 preparatory HPLC to give 1-(3-chloro-4-(2-(2-methoxyethoxy)ethoxy)phenyl)-3-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)urea as a white solid (390 mg, 72% yield): HPLC: Waters Symmetry C18, 5 wn, 3.9×150 mm, 1 ml/min, 240 nm. 30/70 CH3CN/0.1% H3PO4, 5.40 min (99.8%); mp: 188-190° C.; 1H NMR (DMSO-d6) δ 1.92-2.10 (m, 1H, CHH), 2.29-2.47 (m, 1H, CHH), 2.60 (dd, J=2.2, 15.4 Hz, 1H, CHH), 2.82-3.01 (m, 1H, CHH), 3.25 (s, 311, CH3), 3.46 (dd, J=3.7, 5.6 Hz, 2H, CH2), 3.61 (dd. J-3.8, 5.7 Hz, 2H, CH2), 3.73 (d, J=4.7 Hz, 2H, CH2), 4.09 (t, J=4.9 Hz, 2H, CH2), 4.24-4.55 (m, 4H, CH2, CH2), 5.11 (dd, J=5.1, 13.2 Hz, 1H, CH), 6.77 (t, J=5.9 Hz, 1H, NH), 7.04 (d, J=9.1 Hz, 1H, Ar), 7.19 (dd, J=2.5, 9.0 Hz, 1H, Ar), 7.38-7.49 (m, 1H, Ar), 7.51 (s, 1H, Ar), 7.64 (d, J=2.6 Hz, 1H, Ar), 7.69 (d, J=7.7 Hz, 1H, Ar), 8.65 (s, 1H, NH), 10.98 (s, 1H, NH); 11C NMR (DMSO-d6) δ 22.51, 31.20, 42.80, 47.12, 51.56, 58.05, 68.80, 68.85, 69.84, 71.29, 114.66, 117.58, 119.49, 121.24, 121.88, 122.91, 126.89, 130.29, 134.53, 142.38, 144.84, 148.40, 155.25, 167.95, 171.01, 172.86; LCMS: MH=545, 547; Anal Calcd for C26H29ClN4O7+0.4H2O: C, 56.55; H, 5.44; N, 10.15. Found: C, 56.64; H, 5.34; N, 10.15.
