Improved Synthesis Of Dialkyl Phosphinic Acid And Trialkyl Phosphine Oxide

Nickel, Cobalt and Uranium are a kind of important strategic material resourcesto the protection of the national economic development and the national security.Nickel and Cobalt are widely used in aerospace, electronics and alloy, while Uraniumis a key raw material for nuclear energy. Nickel, Cobalt and Uranium are mainlyobtained from ore by solvent extraction with a sort of phosphorus extractant, in whichdialkyl phosphinic acid(DAPA) shows excellent performance of Nickel and Cobaltextraction with very good separation effect. In addition, trialkyl phosphine oxide(TRPO) also show the excellent performance of Uranium extraction.In this article, a synthesis method has been established to obtain dialkylphosphinic acid with hydrated sodium hypophosphite and olefins as main rawmaterial, acetic acid as a solvent, di-tert-butyl peroxide as a radical initiator, and asmall amount of industrial mixed-decene as a catalyst, the yield was90%or more.Seven kinds of dialkyl phosphinic acid were synthesized with greatly shortening thereaction time. The reaction have simple steps, green, atom economy, high purity, easeof separation, with the prospect of industrialization. The structures of all compoundswere confirmed by1H-NMR,13C-NMR,31P-NMR and ESI-MS. A reactionmechanism was proposed for the dialkyl phosphinic acid synthesis reaction.Another synthesis method has been established with dialkyl phosphinic acid andolefins as the main raw materials, chloroform and acetic acid as the mainsolvents,trichloro silane as a reducing agent, di-tert-butyl peroxide as an initiator, asmall amount of industrial mixed-decene as a catalyst, trialkyl phosphine oxides wereprepared via dialkyl phosphonium chloride and dialkyl phosphine oxide intermediates,by bromoalkane addition-hydrolysis and hydrolysis-olefin addition, the yields were80%or more. The reaction is simple steps, green, atom economy, high purity, ease ofseparation, with the prospect of industrialization. The structures of all compoundswere confirmed by1H-NMR,13C-NMR and31P-NMR. And the synthesis conditionsof intermediates have also been optimized.