N n diisopropylethylamine

2-Hexadecyl-octanoic acid (TCI America, 30 mg, 59 μmol), (benzotriazol-1-yloxy) Tris-(dimethylamino)phosphonium hexafluorophosphate (Sigma-Aldrich, 29 mg, 66 μmol), and N,N-diisopropylethylamine (Sigma-Aldrich, 10 μL) were dissolved in anhydrous dichloro-methane (2 mL) and stirred at 40 °C for 10 min under nitrogen atmosphere. A solution of deferoxamine mesylate (Sigma-Aldrich, DFO, 30 mg, 46 μmol) and N,N-diisopropylethyl-amine (10 μL) in anhydrous dimethyl sulfoxide (Sigma-Aldrich, 0.7 mL) was then added and the resulting mixture stirred for 4 h at 40 °C under nitrogen. The cloudy suspension was allowed to cool down to room temperature, and dichloromethane was removed under reduced pressure. Hydrochloric acid (0.1 M, 1 mL) was added, and the mixture was stirred for 10 min at room temperature. The solid was filtered with 0.1 M HCl (3 × 1 mL), dimethyl sulfoxide (3 × 1 mL), water (3 × 1 mL), and, finally, dichloromethane (3 × 1 mL) and dried to yield a white solid (31 mg, 64%). MS–ES⁺: 1074 (M+Na)⁺. MS–ES⁻: 1050 (M–H)⁻, 1086 (M+Cl)^{−. 1}H NMR (CDCl₃/CD₃OD, δ, ppm): 0.55 (t, 6H), 0.92 (br, 60H), 1.06 (br, 6H), 1.27 (m, 6H), 1.32 (m, 6H), 1.76 (m, 1H), 1.80 (s, 3H), 2.15 (t, 4H), 2.46 (t, 4H), 2.87 (m, 6H), 3.29 (m, 6H).