Synthesis of the New Type of Water-Soluble Ligand N,N-Bis-(diphenylphosphinomethyl)-2-aminoethylphosphonic Acid (Ph2PCH2)2NCH2CH2PO3H2 and Its Sodium Salt

The novel water-soluble ligand, N,N-bis(diphenylphosphinomethyl)-2-aminoethylphosphonic acid, (Ph2PCH2)2NCH2CH2PO3H2, had been synthesized in quantitative yield by reaction of 2-aminoethylphosphonic acid with bis(hydroxymethyl)-diphenylphosphonium chloride in water. Its mono- and disodium salts, which can be used as water-soluble ligands for transition metal complex catalysts, were also easily prepared under mild conditions.