scholarly journals The synthesis and characterization of some ortho-substituted phenoxyalkanoic acids and their derivatives

2006 ◽  
Vol 71 (12) ◽  
pp. 1247-1261 ◽  
Author(s):  
Xenia Lupea ◽  
Iuliana Popescu ◽  
Corneliu Tarabasanu ◽  
Ioana Ienascu ◽  
Valentin Badea
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Aromatic Aldehydes ◽  
Ethyl Esters ◽  
Physico Chemical ◽  
Alkanoic Acids ◽  
Halogenated Acids ◽  
New Compounds ◽  
Reaction Media

The synthesis of 2-phenoxyalkanoic acids (ethanoic, propanoic, butanoic) was realized by the reaction of ortho-hydroxybenzamide respectively N-phenyl-o-hydroxybenzamide with ?-halogenated acids in aqueous sodium hydroxide solution. 2-[o-(carbamoyl)phenoxy]-2-methyl- and 2-[o-(phenylcarbamoyl)phenoxy]-2-methyl- propanoic acids were obtained by reaction of the appropriate amide with acetone, chloroform and sodium hydroxide. Ethyl esters of 2-phenoxyalkanoic acids were obtained by the reaction of the amide with ethyl esters of ?-halogenated acids in different reaction media. Starting from the ethyl esters of 2-[2-(N-phenylcarbamoyl) phenoxy]alkanoic acids with hydrazine 2-[2-(N-phenylcarbamoyl)phenoxy]alkanoic acids hydrazides were obtained, which are considered key intermediates for the synthesis of several series of new compounds. Schiff bases and N-imido-derivatives were obtained by condensation of hydrazide with substituted aromatic aldehydes respectively maleic anhydride. The synthesized compounds were characterized by physico-chemical methods (FTIR, NMR and mass spectrometry). .

Equilibrium and Kinetics of the Extraction of Gallium(III) from Sodium Hydroxide Solutions with 7-Dodecenyl-8-quinolinol (Kelex 100)

1993 ◽  
Vol 58 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Aleksandra A. Mitrovic ◽  
Slobodan K. Milonjic ◽  
Zoja E. Ilic ◽  
Radomir V. Stevanovic
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Sodium Concentration ◽  
Extraction Kinetics ◽  
Aqueous Sodium Hydroxide Solution ◽  
Ph Values ◽  
Constant Ph ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

The influence of hydroxide ions concentration of the aqueous sodium hydroxide solution, at constant sodium concentrations, on the gallium extraction with Kelex 100 was examined in the hydroxide concentration range from 0.02 to 0.5 mol dm-3. The percentage of extracted gallium increases from 51% to 98% within the investigated hydroxide concentration range. The influence of sodium concentrations (from 1 to 6 mol dm-3) on the gallium extraction was also studied at constant pH values. The decrease of extracted gallium is slight for the sodium concentration up to 3 mol dm-3, while for the higher ones it is pronounced. The extraction kinetics was studied using a mixer-type apparatus. The rate expression of the extraction reaction of gallium with Kellex 100, for both lower and higher hydroxide concentrations are ascertained.

scholarly journals A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

2016 ◽  
Vol 12 ◽  
pp. 2443-2449 ◽  
Author(s):  
Donghui Pan ◽  
Yanbin Wang ◽  
Guomin Xiao
Keyword(s):  
Organic Solvent ◽  
Sodium Hydroxide ◽  
Anion Exchange ◽  
Organic Waste ◽  
Silver Oxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Product Yield ◽  
Aqueous Sodium Hydroxide Solution ◽  
Aqueous Sodium

We report a green and convenient protocol to prepare 4,7,12,15-tetrachloro[2.2]paracyclophane, the precursor of parylene D, from 2,5-dichloro-p-xylene. In the first bromination step, with H2O2–HBr as a bromide source, this procedure becomes organic-waste-free and organic-solvent-free and can appropriately replace the existing bromination methods. The Winberg elimination–dimerization step, using aqueous sodium hydroxide solution instead of silver oxide for anion exchange, results in a significant improvement in product yield. Furthermore, four substituted [2.2]paracyclophanes were also prepared in this convenient way.

Highly-Purified Natural Rubber by Saponification of Latex: Analysis of Residual Proteins in Saponified Natural Rubber

2008 ◽  
Vol 81 (1) ◽  
pp. 121-137 ◽  
Author(s):  
Jintana Yunyongwattanakorn ◽  
Yasuyuki Tanaka ◽  
Jitladda Sakdapipanich ◽  
Voratep Wongsasutthikul
Keyword(s):  
Natural Rubber ◽  
Sodium Hydroxide ◽  
Room Temperature ◽  
Sodium Hydroxide Solution ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Aqueous Sodium Hydroxide ◽  
Enzyme Linked Immunosorbent Assay ◽  
Nitrogenous Compounds ◽  
Sds Page

Abstract Highly purified natural rubber (NR) was prepared by saponification of fresh latex (FL-latex) and preserved high-ammonia latex (HA-latex) in the presence of surfactant to reduce the residual proteins in resulting solid NR. Saponification of latex diluted to 30% DRC was carried out with 1–7% (w/v) sodium hydroxide at room temperature for 1–7 hr at 70 °C and coagulated with formic acid. The nitrogen content of NR obtained by coagulation of the saponified latex markedly decreased to less than 0.014% by centrifugation of the saponified latex or soaking the coagulum in aqueous sodium hydroxide solution. The nitrogenous compounds from saponified NR (SAP-NR) were extracted with sodium dodecyl sulphate (SDS) aqueous solution and subjected to SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis to check the molecular weight of extracts. The extract from SAP-NR and deproteinized NR by protease (DPNR) for comparison was subjected to the analysis of allergic protein by FIT Kit method, based on Enzyme-Linked Immunosorbent Assay (ELISA) method. No extractable protein was observed in SAP-NR, whereas DPNR contained 1.5 μg/ml proteins. The results from SDS-PAGE analysis and FIT Kit test demonstrated that NR free from allergic proteins is obtainable by saponification of FL-latex with 1.5% NaOH at 70 °C for 1 hr or at room temperature for 24 hr.

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