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Epoxidation of 1,5,9-cyclododecatriene with H2O2in the presence of tungstophosphoric acid (H3PW12O40)

100%
Wołosiak A., Lewandowski G.
Polish Journal of Chemical Technology
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2010
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vol. 12
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issue 3
40-44
EN
The influence of the technological parameters on the epoxidation of 1,5,9-cyclododecatriene (CDT) to 1,2-epoxy-5,9-cyclododecadiene (ECDD) by the phase-transfer catalysis method (PTC) in the presence of tungstophosphoric heteropolyacid (H3PW12O40) and hydrogen peroxide as the oxidizing agent has been presented. The phase-transfer catalyst was Aliquat® 336 (methyltrioctylammonium chloride). The epoxidation of CDT to ECDD in the PTC system proceed under the relatively mild condition: low temperature, lack of solvent, short reaction time.The effect of: the mixing velocity, the molar ratio of CDT:H2O2 and H2O2:H3PW12O40, the nature of the solvent and its concentration, was studied. The most advantageous technological parameters were: the mixing rate 400 - 600 rpm, the molar ratio of CDT:H2O2 = 3:1 - 1.5:1, the molar ratio of H2O2:H3PW12O40 = 200:1 - 400:1, the temperature 40 - 50°C, solvent: dichloromethane or lack of the solvent, dichloromethane concentration: 10 - 50 vol%, reaction time 35 - 50 min. The application of the above-mentioned parameters allows to achieve the yield of 44 - 47% ECDD in relation to introduced CDT.
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Study of Extraction Equilibria in the Reaction of Alkaline Hydrolysis of Activated Amino Acid Esters / Badanie Równowag Ekstrakcji W Reakcji Zasadowej Hydrolizy Aktywowanych Estrów Aminokwasów

58%
Doroshkevich V. S., Baranova O. V., Shendrik A. N., Doroshkevich A. S., Lygina O. S., Lyubchyk S. B.
Chemistry-Didactics-Ecology-Metrology
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2014
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vol. 19
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issue 1-2
69-77
EN
Correlation between observed kinetic effects of phase-transfer catalytic reaction of the alkaline hydrolysis of 4-nitrophenyl ester of N-benzyloxycarbonylglycine-4 in the two-phase system chloroform-borate buffer pH = 10 and a content of ionic forms of catalyst was investigated. The phosphonium salts QX (X = Cl¯, Br¯, I¯) shows high catalytic reactivity. Dependence of the reaction kinetics discussed in the framework of the extraction mechanism with a competitive extraction of a nucleophile ОН¯, nucleofuge 4-NO2C6H4O¯ and anion X¯ of the phase-transfer catalyst.
PL
Zbadano korelację pomiędzy obserwowanym efektem kinetycznym przejścia fazowego katalitycznej reakcji zasadowej hydrolizy estru 4-nitrofenylowego N-benzyloksycarbonylglycyny-4 w dwufazowym układzie chloroform-bufor boranowy, pH = 10, z zawartością jonowych form katalizatora. Sole fosfoniowe QX (X = Cl¯, Br¯, I¯) wykazują wysoką aktywność katalityczną. Zależności kinetyki reakcji przeanalizowano w ramach mechanizmu ekstrakcji z konkurencyjną ekstrakcją nukleofilu ОН¯, grupą odchodzącą 4-NO2C6H4O¯ i anionem X¯ katalizatora przejścia fazowego.
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