To a solution of 5-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]thiophene-2-sulfonyl chloride (2.00 g, 5.85 mmol), DIEA (1.134 g, 8.78 mmol) in DCM (20 mL) was added dodecyl amine (1.41 g, 7.61 mmol) at rt and the reaction mixture was stirred for 2 h at rt. A 1 M aqueous solution of HCl (10 mL) was added and the aqueous layers were extracted with DCM (2×30 mL). The combined organic layers were dried over MgSO4, filtered and concentrated to afford a yellowish oil. This crude product was purified by column chromatography over silica gel (AcOEt/c-Hex 1/4 to 4/1 in about 0.5 h) to give the title compound as a white solid (2.10 g, 73%). 1H NMR (CD3OD, 300 MHz) δ 7.91 (m, 2H), 7.85 (m, 2H), 7.43 (d, 1H, J=3.7 Hz), 7.17 (d, 1H, J=3.7 Hz), 5.05 (s, 2H), 2.90 (t, 2H, J=6.9 Hz), 1.50-1.38 (m, 2H), 1.35-1.16 (m, 18H), 0.86 (t, J=7.9 Hz, 3H) M−(LC/MS): 489.3; M+(LC/MS): 491.2. HPLC (Condition A), Rt: 6.64 min (HPLC purity: 95.9%).
