Phosphonic acids solvent extraction

Mapara, P.M. Godbole, A.G. Swarup, R. Nagar, M.S. Extraction of uranium and plutonium from oxalate bearing solutions using phosphonic acid Solvent extraction, extraction chromatography and infrared studies, J. Radioanal. Nucl. Chem. 240 (1999) 631-635. 

McAlister, D.R., Horwitz, E.P. 2007. Characterization of extraction of chromatographic materials containing bis(2-ethyl-l-hexyl)phosphoric acid, 2-ethyl-1-hexyl (2-ethyl-1-hexyl) phosphonic acid, and bis(2,4,4-trimethyl-l-pentyl)phosphinic acid. Solvent Extraction and Ion Exchange 25(6) 757-769. 

Jayachandran, J. Dhadke, P. M. Solvent extraction separation of cobalt(II) with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A). Chem. Anal. 1999, 44, 157-165. 

Preston, J. S. Solvent extraction of cobalt and nickel by organophosphorus acids. I. Comparison of phosphoric, phosphonic, and phosphinic acid systems. Hydrometallurgy 1982, 9, 115-133. 

A variant solvent formulation was developed in China (INET), involving (2-ethylhexyl)-phosphonic acid 2-ethylhexyl ester (HEHEHP) as the extractant (saponified to 40% with concentrated ammonia), dissolved at 1.5 M in kerosene, to recover, in 43 stages, 99% of Am(III) and remove 90% of Ln(III) from a 0.2 M nitrate feed (pH 1) (237). 

N.V. Thakur, S.L. Mishra, Separation of Co, Ni and Cu by Solvent Extraction Using Di-(2-ethylhexy) Phosphonic Acid, VCSSA Hydrometallurgy, 48(1998),277-289... 

Excluding consideration of a multitude of representatives of solvent extraction classes (water-insoluble alcohols, ethers, acids, esters, ketones and diketones) that have been examined and found to be inadequate in some respect or another, it is the intent here to focus upon only a few representatives of just three classes of extractants (1) neutral phosphorous agents (2) monoacidic orthophosphate and phosphonate esters and (3) primary, secondary, tertiary and quaternary ammonium ion species. 

The 2-(6-formyl-2-pyridyl)-2-(4-tolyl)-l,3-dioxolan (2.5 g) was dissolved in 1,2-dimethoxyethane (10 ml) and added to a solution of the phosphonate carbanion produced from triethyl phosphonoacetate (2.0 g) and sodium hydride (0.22 g) in the same solvent. The mixture was stirred for 2 h, diluted with ether (25 ml) and treated with hydrochloric acid (5 ml, 2 mol). The organic phase was separated, washed with water, dried, and evaporated. The resulting oil was dissolved in ethanol (20 ml) containing concentrated hydrochloric acid (3 ml) and water (3 ml). After heating on the steam bath for 10 min, the solution was diluted with ice water, rendered alkaline with sodium bicarbonate solution, and extracted with ether. Evaporation gave 1.0 g ((E)-3-(6-(4-toluoyl)-2-pyridyl)acrylate as colourless platelets, melting point 108°-111°C (crystallized from cyclohexane). 

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