GENERAL STEPS: 9-Fluorenylmethyl-N-succinimidyl carbonate (Fmoc-OSu, 6.55 g, 21.9 mmol) and sodium bicarbonate (NaHCO3, 2.39 g, 28.5 mmol) were added to a mixture of acetone (90 mL) and water (90 mL) of 12-aminodododecanoic acid (4.71 g, 21.9 mmol). The reaction mixture was stirred at room temperature for 20 hours. Upon completion of the reaction, the pH was adjusted to 4-5 with concentrated hydrochloric acid (HCl) to quench the reaction, followed by extraction of the resulting precipitate with ethyl acetate (EtOAc, 3 x 50 mL). The organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: hexane-ethyl acetate, 3:1) to afford FMOC-12-aminododecanoic acid (4.20 g, 43% yield) as a white solid. The structure of the product was confirmed by 1H NMR and 13C NMR [28].
