Reaction Steps
To a solution of di(5-azidopentyl)amine (0.12 g, 0.49 mmol) in anhydrous DMF (5 mL) of were added biotin (0.12 g, 0.41 mmol), PyBOP (0.25 g, 0.49 mmol) and Et3N (0.23 mL, 1.64 mmol). The mixture was stirred for 22 h at room temperature under argon, and then concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, CH2Cl2/MeOH=13:1) to give biotin-diazide compound 25 (0.15 g, 79%). C20H35N9O2S; pale yellow oil; 1H NMR (CDCl3, 600 MHz) δ 4.48 (dd, J=7, 5 Hz, 1 H), 4.29 (dd, J=7, 5 Hz, 1 H), 3.28 (t, J=7 Hz, 4 H), 3.25 (t, J=7 Hz, 4 H), 3.20 (t, J=7 Hz, 2 H), 2.89 (dd, J=12, 5 Hz, 1 H), 2.71 (d, J=12 Hz, 1 H), 2.29 (t, J=7 Hz, 2H), 1.84 (br s, 3 H), 1.50-1.67 (m, 8 H), 1.43-1.44 (m, 2 H), 1.32-1.38 (m, 4 H); 13C NMR (CDCl3, 150 MHz) δ 172.4, 163.2, 61.8, 60.1, 55.3, 51.2, 47.0, 46.2, 45.6, 40.5, 32.5, 28.7, 28.6, 28.3, 27.3, 26.4, 25.1, 24.1. ESI-HRMS calcd for C20H36N9O2S: 466.2707, found: m/z 466.2703 [M+H]+.
