Pharmacologically interesting compounds—I: High resolution mass spectra of phenothiazines

The mass spectra of twenty-six commercially available medicinal phenothiazines have been determined at high resolution. In each compound, the side chain attached to the 10-position of the phenothiazine ring contains nitrogen and fission of the C? C bond α to this nitrogen gives in most cases the base peak. Some of the compounds are also substituted at the 2-position and this substituent generally remains intact, though some substituents such as acetyl, propionyl, methoxyl and methylthio can undergo fragmentation. Fragmentations fall into three groups; those which give ions representing a part of the side chain; those which give ions representing the intact phenothiazine ring with part of the side chain attached; those which give ions representing a partially fragmented ring system.     

Ion exchange in dimethylsulfoxide media. I

Summary Distribution ratios between Dowex 50 W-X 8 resin and DMSO-H₂O-HCl systems have been determined for Mg, Ca, Sr, Ba, Ga, In, Sn(II) and Pb(II) as a function of both DMSO content and HCl-molarity. At high DMSO concentrations and high HCl concentrations theD values for all metal ions were not much different from those in corresponding aqueous systems. However, at lower and intermediate HCl concentrations (0.10 to 0.60M) D values differed greatly from those in aqueous systems, especially in the range from 20 to 50 mole% DMSO. Maxima in the logD vs. mole% DMSO plots at constant HCl concentrations were obtained for all cations except Sn(II) and Pb(II). Separation procedures for various pairs and combinations of cations seem feasible in DMSO-media [e. g., Ga/In and Sn(II)/Pb(II)] and the DMSO-water system is suggested as a very promising novel solvent medium for ion exchange separations.

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Zusammenfassung Für Mg, Ca, Sr, Ba, Ga, In, Sn(II) und Pb(II) wurden die Verteilungsverhältnisse zwischen Dowex 50 W-X 8 und Dimethylsulfoxid—Wasser—Salzsäure in Abhängigkeit vom DMSO-Gehalt und der Salzsäuremolarität bestimmt. Bei hohen DMSO-Konzentrationen und hohen HCl-Konzentrationen unterscheiden sich die Verteilungskoeffizienten (D) aller Metallionen nicht sehr von denen in entsprechenden wäßrigen Systemen. Aber bei niederen und mäßigen HCl-Konzentrationen (0,10-bis 0,60-m) istD sehr verschieden gegenüber wäßrigen Systemen, besonders bei Anwesenheit von 20 bis 50 Mol-% DMSO. Trägt man logD gegen Mol-% DMSO bei konstanter HCl-Konzentration auf, so erhält man für alle Metalle außer Sn(II) und Pb(II) Maxima. Trennungsverfahren für verschiedene Ionenpaare und -gemische scheinen in DMSO-hältigem Plasma durchführbar zu sein, z. B. Ga/In und Sn(II)/Pb(II). Wäßrige DMSO-Systeme sind neue, vielversprechende Lösungsmittel für Trennungen mit Hilfe von Ionenaustauschern.

     

Stereochimie de l'hydrogenation des (±) Δ3(3a)-hydrindenones-4. Comparaison avec le cas de la (+) methyl-3 Δ3(3a)-hydrindenone-4 et de ses dioxolannes

We show that the four studied 4-hydrindenones (with or without a methyl substituant at C3 or C7a) give by hydrogenation on Raney nickel or on Pd/C, in various solvants, the cis 4-hydrindanones, by a kinetically controlled process. During the hydrogenation, the double bond can migrate only in the positions conjugated to the carbonyl group.In contrast, when the carbonyle is protected as a dioxolanne, the double bond is free to migrate around the five membered ring. In spite of this mobility the optical purity of the saturated dioxolannes formed is high. In the case of the (+)3-methyl Δ^3(3a) 4-hydrindenone, the enantiomeric hydrindanones $\text{9a}$ obtained by direct hydrogenation or with isomerization of the double bond are not the same. Therefore, the optical purity of the product is low, but its value allows an estimation of the relative importance of the two reaction pathways.     

Détermination de l'énergie de conjugaison des acides naphtoǐques

The present paper deals with the experimental and theoretical determination of energies of conjugation of organic molecules.A computation process has been applied, first to simple molecules comprising an hydrocarbon (styrene), an oxygen function (benzaldehyde) and a nitrogen function (aniline). The results are compared with those obtained from the literature.The application of this computation process to naphthoic acids permits the determination of energies of conjugation and isomerization of these molecules.     

[3+2]-cycloreactions of 1,2-diacylcyclopropenes with ynamines. Aminofurane- versus aminocyclopentadiene-formation

Electron deficient 1,2-diacylcyclopropenes represent synthetic equivalent for both acylcarbenes and vinylcarbenes; in their cycloreaction with ynamines aminofuranes and/or aminocyclopentadienes are formed.     

A New Method to Prepare Transition Metal Salts of Bulk and Supported Heteropolyacids. Application to the Catalysis of the Oxidative Dehydrogenation of Isobutyric Acid

Transition metal salts of heteropolyacids have been prepared taking into account the strong acidic and cation exchanging properties of the solid heteropolyacids. The exchange between protons and the transition metal cation is carried out by stirring a suspension of the hydrated heteropolyacid in a solution of the metal acetylacetonate complex in toluene. The exchange occurs on the surface of the solid particles and diffusion of protons and metal cations into the hydrated lattice leads to the substitution of all the protons. The method can be utilized in order to prepare supported vanadyl and copper molybdophosphates from supported heteropolyacids and they have been studied in the catalysis of the oxidative dehydrogenation of isobutyric acid. The effect of vanadyl counter-ions on the catalytic behavior is the same as observed with bulk catalysts but, on the contrary, copper supported molybdophosphate shows an acid catalytic activity not observed with bulk catalysts.     

A new method to study antioxidant capability: hydrogen transfer from phenols to a prefluorescent nitroxide

[reaction: see text]. Rate constants for hydrogen abstraction from phenols by a prefluorescent-TEMPO probe are reported. The nitroxide is employed as a potential model of peroxyl radicals. The probe works by nitroxide suppression of the fluorescence of the chromophore. The fluorescence is restored when the nitroxide abstracts a hydrogen atom to produce the diamagnetic hydroxylamine. The phenols studied in this project exhibited rate constants between 0.003 and 0.2 M(-1) s(-1). A deuterium isotope effect of 10 for TROLOX confirms that the mechanism is dominated by hydrogen transfer.     

Cinnamate ester containing liquid crystalline side chain polymers

The synthesis of methacrylate esters of 4-cyanophenyl-(4-(ω-hydroxyalkyloxy)) cinnamates, with spacer lengths of 2 and 6 methylene units and the synthesis of the corresponding acrylate ester with a spacer of 2 methylene units are described. The methacrylate monomers were polymerized by free radical polymerization, both as homopolymers and as copolymers with the analogous benzoate monomer of spacer length 6. The acrylate ester could not be polymerized successfully under the same reaction conditions. Polymers were characterized by NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermo-optic observations. Of the monomers prepared, only the cinnamate with a hexamethylene spacer shows a mesophase, seen on supercooling of the melt. All of the polymers prepared were liquid crystalline, with smectic behavior predominating in the polymethacrylates with the longer spacer group. A narrow nematic region is seen just below the clearing temperature with a range of 3–9°C, nematic character is increased in the copolymer series with the degree of incorporation of the cinnamate monomer with the spacer group of length 2.     

Synthesis of some benzimidazole‐, benzothiazole‐ and pyridine‐derived chelating agents

Procedures are given for the preparation of new linear bidentate, tetradentate and tripodal heptadentate ligands incorporating benzimidazole, benzothiazole and pyridyl groups. The compounds were characterized by their nmr, uv and mass spectra. The crystal and molecular structure is reported for a chiral benzothiazole derived from camphoric acid.     

Comparison of purge and trap GC/MS and spectrophotometry for monitoring petroleum hydrocarbon degradation in oilfield produced waters

Results of using a field spectrophotometer and its appropriate protocols as a surrogate method for an oilfield produced water treatment process is presented. Methylene chloride extractions of the produced water before and after treatment maintained a yellow color pigment that was directly proportional to the hydrocarbon concentration. From this, an absorption spectrum and standard curve were developed. A resultant linear plot of the standard curve indicated that there is an excellent correlation (r²=0.9847) between the varying concentrations and the associated absorbance values at a wavelength of 400 nm. Total n-alkane concentration comparisons between the laboratory GC/MS analysis and the spectrophotometry analysis generated data of similar accuracy and precision at concentrations ranging from 1 to 137 mg/l (alpha=0.05). Linear comparisons between GC/MS and spectrophotometric coefficients were near unity, with the constant being near zero, with a correlation coefficient (r²) of 0.99. Based on this study, spectrophotometry is a complimentary method to GC/MS for determining total n-alkane concentrations in oilfield produced water samples.