A series of hitherto unknown isomeric monobutyl esters of octylphosphonates was prepared by partial saponification of di-Bu octylphosphonates either with NaOH or with ethanolamine for the quant. structure-reactivity studies. The alkaline hydrolysis was markedly accelerated by a quaternary ammonium salt-tetrabutylammonium bromide. The phase transfer catalyzed hydrolysis provides a convenient route for the preparation of mono-esters of alkylphosphonates. The completion of the reaction was successfully monitored by silicon-loaded paper chromatog. The mass spectra of the title compounds and the IR spectra of corresponding mono-sodium salts were studied and discussed.

Key words: HYDROLYSIS, BUTYL, ORGANO PHOSPHORUS COMPOUNDS, PHOSPHONIC ACID ESTER, PHASE TRANSFER CATALYSIS, ETHANOL P, OCTANE P, SAPONIFICATION, SODIUM HYDROXIDE, NSFC