On the lead tetraacetate and related oxidations of aromatic ketoximes

1968 ◽  
Vol 46 (23) ◽  
pp. 3719-3726 ◽  
Author(s):  
M. M. Frojmovic ◽  
G. Just
Keyword(s):  
Nitric Oxide ◽  
Acetic Acid ◽  
Nitrogen Dioxide ◽  
Molecular Oxygen ◽  
Glacial Acetic Acid ◽  
Methylene Chloride ◽  
Lead Tetraacetate ◽  
Side Reactions ◽  
Oxidizing Agents

Fluorenone and benzophenone oxime react in glacial acetic acid with lead tetraacetate to give parent ketones, geminal dinitromethanes, iminyl ketal derivatives (9,9-difluorenylideniminoxylfluorene and 1,1-bis(diphenylmethylideniminoxyl)-diphenylmethane), and minor amounts of oxime O-acetate. Benzophenone nitrimine is also formed but only in the absence of oxygen. Side reactions due to nitric oxide, oxygen, and nitrogen dioxide take place. Separate studies with these oxidizing agents have therefore been conducted. The lead tetraacetate oxidation of these oximes in methylene chloride (or any other solvent) is complete with a half-mole equivalent of lead tetraacetate, is insensitive to molecular oxygen, and affords mainly parent ketone and ketazinemonoxides. No ketazine-bis-N-oxides, obtained from the ferricyanide oxidation of these oximes, are formed. The model oximes, benzil anti-monoxime, xanthone oxime, and indanone oxime have been studied in the light of these observations. Mechanisms involving iminoxyl radicals have been postulated for all reactions studied.

scholarly journals Thin layer chromatographic compatibility study in preformulation of new transdermal therapeutic systems

2020 ◽  
Vol 66 (1) ◽  
pp. 23-29
Author(s):  
Octavia-Laura Moldovan ◽  
Diana-Nicoleta Brihan ◽  
Nicoleta Todoran ◽  
Aura Rusu
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Mobile Phase ◽  
Glacial Acetic Acid ◽  
Methylene Chloride ◽  
Hydroxyethyl Cellulose ◽  
Compatibility Study ◽  
Chemical Interactions ◽  
Miconazole Nitrate ◽  
Active Substances

AbstractObjective: The compatibility of four binary active substances combinations adapalene – levofloxacin (ADP-LFX), adapalene – miconazole nitrate (ADP-MCZ), levofloxacin – meloxicam (LFX-MLX) and levofloxacin – miconazole nitrate (LFX-MCZ) was analysed to be comprised in new transdermal therapeutic systems. Also, the compatibility of selected active substances and four polymeric excipients (hydroxypropyl methyl-cellulose - HPMC 15000, hydroxypropyl methylcellulose - HPMC E5, ethyl cellulose - EC 10, and hydroxyethyl cellulose – HEC) was studied.Methods: Thin layer chromatographic method (TLC) and four selected mobile phases were used. On the plate (in situ) were obtained the binary combinations (active substances and active substance-polymer).Results: A good compatibility of ADP-LFX was found using ammonia : methanol : acetonitrile : methylene chloride 2:4:1:4 mobile phase. Using chloroform : acetone : glacial acetic acid 34:4:3 on the chromatogram of ADP-MCZ, only ADP spots appeared but without changes in the shape of the spots and Rf values. Any modifications of LFX and MLX spots (from LFX-MLX mixture) had been observed using toluene : glacial acetic acid : methanol 11:1:0.5 mobile phase, although LFX spots have remained on the baseline. Only LFX spots were visible from LFX-MLX and LFX-MCZ mixtures (ammonia : methanol : acetonitrile : methylene chloride 2:4:1:4 mobile phase). Distinctive spots were observed for ADP, LFX and MLX with variable results from no chemical interactions to limited chemical interactions when the compatibility with polymers was verified.Conclusions: ADP-LFX and LFX-MLX mixtures were found to be compatible. ADP with HPMC polymers and LFX with HPMC E5 and HEC had presented excellent compatibility; for the other binary combinations, different analytical methods will be necessary.

Iodimetric determinations in organic solvents: Determination of manganese oxidation states in methylene chloride solutions

1990 ◽  
Vol 68 (1) ◽  
pp. 79-81 ◽  
Author(s):  
Joaquin F. Perez-Benito ◽  
Enrique Brillas ◽  
Conchita Arias
Keyword(s):  
Acetic Acid ◽  
Quaternary Ammonium ◽  
Glacial Acetic Acid ◽  
Methylene Chloride ◽  
Oxidation States ◽  
Manganese Oxidation ◽  
Chloride Solutions ◽  
Tetrabutylammonium Iodide ◽  
Organic Solutions

An iodimetric technique has been developed to quantitatively analyze the oxidants present in organic solutions. Addition of excess tetrabutylammonium iodide and excess glacial acetic acid results in the formation of tetrabutylammonium triiodide, whose concentration can be measured spectrophotometrically at 295 or 365 nm. Application of this technique to the determination of the final oxidation state of manganese in permanganate reactions in methylene chloride solutions is described. The equilibrium constant for formation of tetrabutylammonium triiodide in methylene chloride has been measured: K = (3.48 ± 0.12) × 104 at 25.0 °C. Keywords: iodimetric determinations, manganese oxidation states, methylene chloride, quaternary ammonium permanganate, quaternary ammonium triiodide.

The reaction of acetic acid and nitrogen dioxide

1970 ◽  
Vol 48 (21) ◽  
pp. 3459-3461
Author(s):  
R. N. Pandey ◽  
Donald Barton
Keyword(s):  
Nitric Oxide ◽  
Acetic Acid ◽  
Nitrogen Dioxide ◽  
Vapor Phase

Nitric oxide was found to be an autocatalyst in the reaction of acetic acid and nitrogen dioxide at 470 and 527 °K in the vapor phase. The observed products, in addition to NO, were CO, CO2, and CH3NO2.

scholarly journals Effect of Changing Solvents on Poly(-Caprolactone) Nanofibrous Webs Morphology

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
A. Gholipour Kanani ◽  
S. Hajir Bahrami
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Glacial Acetic Acid ◽  
Methylene Chloride ◽  
Polymer Concentration ◽  
Average Diameter ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Poly Caprolactone ◽  
Successful Production

Polycaprolactone nanofibers were prepared using five different solvents (glacial acetic acid, 90% acetic acid, methylene chloride/DMF 4/1, glacial formic acid, and formic acid/acetone 4/1) by electrospinning process. The effect of solution concentrations (5%, 10%, 15% and 20%) and applied voltages during spinning (10 KV to 20 KV) on the nanofibers formation, morphology, and structure were investigated. SEM micrographs showed successful production of PCL nanofibers with different solvents. With increasing the polymer concentration, the average diameter of nanofibers increases. In glacial acetic acid solvent, above 15% concentration bimodal web without beads was obtained. In MC/DMF beads was observed only at 5% solution concentration. However, in glacial formic acid a uniform web without beads were obtained above 10% and the nanofibers were brittle. In formic acid/acetone solution the PCL web formed showed lots of beads along with fine fibers. Increasing applied voltage resulted in fibers with larger diameter.

THE EFFECT OF MOLECULAR OXYGEN ON THE REACTION OF OXYGEN ATOMS WITH cis-2-PENTENE

1959 ◽  
Vol 37 (5) ◽  
pp. 953-965 ◽  
Author(s):  
S. Sato ◽  
R. J. Cvetanović
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Nitrogen Dioxide ◽  
Molecular Oxygen ◽  
Reaction Mechanisms ◽  
Room Temperature ◽  
Pressure Independent ◽  
Decomposition Of Nitrous Oxide ◽  
Oxygen Atoms

The effect of the presence of nitrogen, oxygen, and nitric oxide on the reaction between cis-2-pentene and oxygen atoms has been investigated at room temperature (25 ± 2 °C). For production of oxygen atoms use was made of mercury-photosensitized decomposition of nitrous oxide and of the photolysis of nitrogen dioxide at 3660 Å.In the N2O work, the presence of molecular oxygen induced the formation of acetaldehyde, propanal, methanol, and ethanol. In the NO2 work, the amounts of acetaldehyde, propanal, and ethyl nitrate formed increased rapidly with increasing pressure of molecular oxygen. Possible reaction mechanisms for the formation of these compounds are discussed.Additional information was obtained on the pressure-independent fragmentation in the reaction of oxygen atoms with cis-2-pentene.

A Simple Method to Prepare Affinity Resins on Cellulose Basis

1984 ◽  
Vol 39 (11-12) ◽  
pp. 1048-1051 ◽  
Author(s):  
Karl Eisele ◽  
Fernando Dias Costa ◽  
Carlos Pascual ◽  
Beatus Ofenloch-Hähnle
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Glacial Acetic Acid ◽  
Androgen Receptors ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Low Molecular Weight ◽  
Amino Acid Residues ◽  
Simple Method

Abstract Affinity resins with different spacer arms were synthesized analogues to the solid phase peptide synthesis using aminoethyl cellulose or carboxymethyl cellulose as matrix. The spacer arms could be varied in length and rigidity. Especially spacer arms consisting of poly am ino acids can be synthesized with a defined amount of amino acid residues specifically in the low molecular weight ranges. The method is also applicable to other matrices w hich are not susceptible to 1 ɴ HCl in glacial acetic acid, trethylamine, methylene chloride and dimethylformamide. The synthesis of affinity resins with different spacer arms for the purification of androgen receptors is described as an example of the method.

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