Organo-phosphate precursors are of growing interest for sol-gel preparation of phosphate-based crystals and glasses. Using P-31 NMR, C-13 NMR, and FT-IR spectroscopy, we investigated the optimal conditions for precursors synthesis from liquid saturated aliphatic alcohols and P2O5. The best results were obtained by using ethanol or 2-butanol as the alcohol. Starting from the ethanol-derived precursor, we synthesized boron orthophosphate, BPO4, which for the first time has been obtained directly by a sol-gel route.