Reaction Steps
To a stirred mixture of 3-(5-aminomethyl-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione methanesulfonate (0.37 g, 1.0 mmol) and 4-(tert-butyl) phenyl isocyanate (0.18 g, 1.0 mmol) in DMF (20 mL) was added triethylamine (0.22 g, 2.2 mmol) at rt under nitrogen. After 2 h, 4% aqueous HCl (30 ml) was added and the solids were filtered and dried in vacuo providing 1-(4-tert-butyl-phenyl)-3-[2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-5-ylmethyl]-urea as a white solid, (0.34 g, 76% yield); mp 254-256° C.; HPLC, Waters Symmetry C-18, 3.9×150 mm, 5 μm, 1 ml/min, 240 nm, 40/60 CH3CN/0.1% H3PO4, 7.71 (96.94%); 1H NMR (DMSO-d6) δ 1.24 (s, 9H), 1.97-2.01 (m, 1H), 2.35-2.45 (m, 1H), 2.54-2.62 (m, 1H), 2.85-2.97 (m, 1H), 4.30 (d, 2H, J=17.3 Hz), 4.45 (d, 2H, J=17.3 Hz), 5.10 (dd, 1H, J=12.9 Hz, J=4.5 Hz), 6.68 (t, 1H, J=4.8 Hz), 7.23 (dd, 2H, J=8.4 Hz, J=1.5), 7.31 (dd, 2H, J=8.4 Hz, J=1.5 Hz), 7.44 (d, 1H, J=7.8 Hz), 7.51 (s, 1H), 7.69 (d, 1H, J=7.8 Hz), 8.54 (s, 1H), 10.98 (s, 1H); 13C NMR (DMSO-d6) δ 22.5, 31.2, 31.3, 33.8, 42.7, 47.1, 51.6, 117.6, 121.8, 122.9, 125.2, 126.9, 130.3, 137.7, 142.4, 143.4, 144.9, 155.3, 167.9, 170.9, 172.8; LCMS: MH=449; Anal. Calcd for C25H28N4O4+0.5H2O: C, 65.63; H, 6.39; N, 12.25. Found: C, 65.24; H, 6.17; N, 12.29.
