Membrane transport of dicarboxylic and α-hydroxy carboxylic acids induced by α-amino phosphonates

New alpha-amino phosphonates containing different alkyl and aryl substituents at the alpha-carbon atom were synthesized in high yields by the Kabachnik-Fields and Pudovik reactions. These compounds were studied as carriers of several alpha-hydroxy carboxylic and dicarboxylic acids through liquid impregnated membranes. These alpha-amino phosphonates studied are capable of molecular recognition of oxalic acid among structurally similar alpha-hydroxy carboxylic and dicarboxylic acids. The efficiency and selectivity of mass transfer of oxalic acid increase with an increase in the lipophilicity of the alpha-amino phosphonate.