A facile synthesis of ω-aminoalkyl ammonium hydrogen phosphates

A series of ω-aminoalkyl ammonium hydrogen phosphates were synthesized through a simple and efficient three-step method. The starting materials, ω-aminoalkyl alcohols (AC-n, with carbon number n = 3, 4, 5, 6), were amino-protected with 9-fluorenylmethyl chloroformate (Fmoc-Cl), followed by phosphorylation with POCl3 and deprotection in piperidine/DMF. The structures of each intermediate and final product were confirmed by 1H NMR, FTIR and mass spectrum. The yield of each step was about 77–92%, with a total yield higher than 56%. This new method was superior in low-cost raw materials, mild reaction temperatures (0–25 °C) and easy purification methods.