Hydrogen peroxide coordination-calcium salt precipitation for deep phosphorus removal from crude sodium tungstate solution

The preparation of the key intermediate for spin labeling, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (2), was reinvestigated using sodium tungstate or phosphotungstic acid with or without either Trilon or Triton B. A two-fold and a 3.5-fold molar excess of a 30% aqueous hydrogen peroxide solution was used. The oxidation of 4-hydroxy-2,2,6,6-tetramethylpiperidine (1) with a two-fold molar excess of a 30% aqueous hydrogen peroxide solution in the presence of sodium tungstate alone, under vigorous stirring for two hours, is the superior method (A) for the preparation of 2 in virtually quantitative yield.

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Simulating calcium salt precipitation in the nephron using chemical speciation

Urological Research ◽

10.1007/s00240-010-0359-1 ◽

2011 ◽

Vol 39 (4) ◽

pp. 245-251 ◽

Cited By ~ 10

Author(s):

Allen L. Rodgers ◽

Shameez Allie-Hamdulay ◽

Graham Jackson ◽

Hans-Göran Tiselius

Keyword(s):

Chemical Speciation ◽

Calcium Salt ◽

Salt Precipitation

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Kinetics of the oxidation of dimethyl sulfoxide with aqueous hydrogen peroxide catalyzed by sodium tungstate

Canadian Journal of Chemistry ◽

10.1139/v81-104 ◽

1981 ◽

Vol 59 (4) ◽

pp. 718-722 ◽

Cited By ~ 20

Author(s):

Yoshiro Ogata ◽

Kazushige Tanaka

Keyword(s):

Hydrogen Peroxide ◽

Dimethyl Sulfoxide ◽

Sodium Tungstate ◽

Catalytic Amount ◽

Active Oxygen ◽

Probable Mechanism ◽

Polarographic Study ◽

Aqueous Hydrogen Peroxide ◽

First Order ◽

Kinetics Of

The oxidation of dimethyl sulfoxide (DMSO) by hydrogen peroxide in the presence of a catalytic amount of sodium tungstate (Na2WO4) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction is first-order with respect to the substrate and the catalyst, but independent of the concentration of hydrogen peroxide which is present in excess of the catalyst. The polarographic study implies that in solutions two main kinds of peroxytungstic acids (H2WO5 and H2WO8) are formed which contain active oxygen in ratios (active oxygen):(Na2WO4) of 1:1 and 4:1, respectively. The effect of acidity on the oxidation rate and a probable mechanism involving a rate-determining attack of peroxytungstic acids are discussed.

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Reactions of Hydrogen Peroxide. IV. Sodium Tungstate Catalyzed Epoxidation of α,β-Unsaturated Acids

The Journal of Organic Chemistry ◽

10.1021/jo01083a017 ◽

1959 ◽

Vol 24 (1) ◽

pp. 54-55 ◽

Cited By ~ 134

Author(s):

GEORGE B. PAYNE ◽

PAUL H. WILLIAMS

Keyword(s):

Hydrogen Peroxide ◽

Sodium Tungstate

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Oxidative Iodination of Aromatic Amides Using Sodium Perborate or Hydrogen Peroxide with Sodium Tungstate†

Journal of Chemical Research Synopses ◽

10.1039/a707933h ◽

1998 ◽

pp. 204-205 ◽

Cited By ~ 14

Author(s):

Philipp Beinker ◽

James R. Hanson ◽

Nadja Meindl ◽

Inmaculada C. Rodriguez Medina

Keyword(s):

Hydrogen Peroxide ◽

Sodium Tungstate ◽

Sodium Perborate ◽

Oxidative Iodination

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Attempted Synthesis and Unexpected β-Fragmentation of a Hindered β-Keto Nitroxide

Australian Journal of Chemistry ◽

10.1071/ch17203 ◽

2017 ◽

Vol 70 (10) ◽

pp. 1106 ◽

Cited By ~ 1

Author(s):

Chris Edwards ◽

Peter C. Healy ◽

W. Ken Busfield ◽

Ezio Rizzardo ◽

San H. Thang ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Ring Opening ◽

Sodium Tungstate ◽

Crystallographic Analysis ◽

High Yield ◽

Fragmentation Mechanism ◽

Pentanoic Acid ◽

X Ray ◽

Ring Opening Reaction

The attempted synthesis of a β-keto imidazolidinone nitroxide by oxidation of the β-hydroxy imidazolidinone precursor with hydrogen peroxide and sodium tungstate led to an unexpected ring-opening reaction to produce 1,4-diazaspiro[4.5]dec-1-en-3-oxo-2-pentanoic acid 1-oxide (13) in high yield. The structure of 13 was confirmed by X-ray crystallographic analysis. A β-fragmentation mechanism is suggested for the oxidative ring-opening reaction.

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