The thermal decomposition of the 2-methyl-8-quinolinol (8-hydroxyquinaldine) chelates of scandium,thorium, uranium (VI) and the rare earth elements

The thermal decomposition of the 2-methyl-8-quinolinol (8-hydroxyquinaldine) chelates of scandium, thorium, uranium(VI), yttrium and the rare earth elements was studied on the thermobalance. It was found that the scandium and uraniurn(VI) chelates can lose the extra molecule of solvation by thermal decomposition. The thorium chelate was found to be the most stable of all the chelates studied. The temperature limits for the chelates and the minimum oxide level temperatures are given.     

Synthesis of Diazadi(and tri)thiacrown Ethers Containing Two 5-Substituent(or 2-methyl)-8-hydroxyquinoline Side Arms

Abstract

Sixteen new diazadi(or tri)thiacrown ethers containing two 5-substituent(or 2-methyl)-8-hydroxyquino-lin-2-ylmethyl side arms have been prepared by a three-step process. First, the appropriate bis(α-chloroamide)s were treated with five dimercaptans in base to form macrocyclic di(or tri)thiadiamides. The macrocyclic diamides were reduced by BH₃-THF to form 1,7-diaza-4-oxa-10,13-dithia-cyclopentadecane (11); 1,7-diaza-4,13-dioxa-10,16-dithiacyclooctadecane (12); 1,7-diaza-4-oxa-10,13,16-trithiacyclooctadecane (13); 1,7-diaza-4,13,16-trioxa-10,19-dithiacycloheneicosane (14); and 1,10-diaza-4,7-dioxa-13,16-dithiacyclooctadecane (15). The diazadi(or tri)thiacrown ethers were then treated with 8-hydroxyquinoline, 8-hydroxy-5-methylquinoline, 5-chloro-8-hydroxyquinoline, and 8-hydroxyquinaldine in the presence of paraformal-delyde in refluxing benzene to form the bis(8-hydroxy-5-substituent(or 2-methyl)quinolin-7-ymethy)-substituted diazadi(or tri)thiacrown ethers 16-31. The crown ethers containing two 8-hydroxyquinoline or 8-hydroxyquinaldine side arms proved to be mixtures of about 90% bis(8-hydroxyquinolin-7-ylmethyl)-substituted crown ethers; 9% mixed (8-hydroxyquinolin-7-ymethyl)-substituted and (8-hydroxyquinolin-5-ylmethyl)-substituted crown ethers; and 1% bis(8-hydroxyquinolin-5-ylmethyl)-substituted crown ethers.     

The thermal decomposition of the 5,7-dihalo-8-quinolinol rare earth metal chelates

The thermal decomposition of the 5,7-dichloro-, 5,7-dibromo- and 5,7-duodo-8-quinohnol chelates of lanthanum, cerium, praseodymium, neodymium, samarium and yttrium was investigated on the thermobalance. The chelates decomposed in the temperature range from 65 to 125°C while the oxide levels were obtained from 395 to 805°C Although the chelate thermal stability temperatures varied little with the chelating agent, the minimum oxide level temperatures were largely dependent on the halogen substitution on the 8-quinolinol molecule. Results of this study were correlated with previous studies on the rare earth metal chclatcs with 8-quinolinol and 2-methyl-8-quinolinol.     

8-Hydroxyquinoline and 8-hydroxyquinaldine as reagents for the colorimetric estimation of chromium

Summary A simple colorimetric method for the estimation of Cr^III ions, employing 8-hydroxyquinoline and 8-hydroxyquinaldine, has been described. It has been shown that upto a concentration ratio of 13, the presence of Al^III ions, does not interfere with the 8-hydroxyquinaldine reagent. The method has been further shown not to be interfered by the presence of Ce^III, Ni^II, W^VI, Mn^II, Th^IV, Zn^II, Tl^I, and Ba^IIions, but the presence of Fe^II, Fe^III, U^VI, Cu^II, Co^II and Mo^VIions affects the results. It is found to be necessary to heat the reaction mixture, before carrying out the extraction process.     

Chelate von Chinolin-8-01-Derivaten. V [I]. Komplexbildung und Extraktion von Nickel mit alkylsubstituierten Chinolin-8-olen

Chelates of 8-Quinolinol Derivatives. V. Coordination and Extraction of Nickel with Alkylsubstituted 8-Quinolinols . The nickel chelates of 2-, 5-, and 7-methyl-8-quinolinols and of a series of 7-alkyl-8-quinolinols were synthesized in the water-free state. Spectroscopic and magnetochemical differences between the compounds with 2-, 5-, and 7-methyl-8-quinolinols were explained by structural peculiarities. For the nickel chelates with 7-alkyl-8-quinolinols a somewhat distorted square-planar structure is supposed. To characterize the influence of substituents the adduct formation with pyridine was studied. For the extraction of nickel with 8-quinolinols the kind of the alkyl or alkenyl substituent in 7-position has no distinct influence on the state of the extraction equilibrium but it impairs the quickness of the extraction with increasing hydrophobicity.     

Extraktionsverhalten methylsubstituierter chinolin-8-ole gegenüber kupfer

Extraction behavior of methyl-substituted 8-quinolinols towards copper). The distribution of 2-, 5-, and 7-methyl-8-quinolinols and the extraction of their copper chelates are reported for the chloroform/water system. The stability constants for the copper complexes were calculated. From the acidity and distribution constants of the isomeric 8-quinolinols and the stability and extraction constants of the copper chelates, 7-methyl-8-quinolinol provides the highest complex stability and is the best extractant of the series.     

Chelate von Chinolin-8-ol-Derivaten. VI. Komplexbildung und Extraktion von Kupfer mit alkyl- bzw. alkenylsubstituierten Chinolin-8-olen

Chelates of 8-Quinolinol Derivatives. VI. Complex Formation and Extraction of Copper with Alkyl and Alkenyl Substituted 8-Quinolinols The copper chelates of a series of 7-substituted alkyl and alkenyl 8-quinolinols as well as 2-, 5-, and 7-methyl-8-quinolinols were synthesized and the chemical bonding was studied by EPR spectroscopy in chloroform and pyridine solution. Spectral changes in the chloroformic solutions of the chelates produced by pyridine are the result of a slow destruction reaction. For the extraction of copper in the chloroform/water system the extraction parameters as well as distribution data of the ligands were determined.     

Inorganic analysis in organic solvents : 8-hydroxyquinaldine as a reagent for the determination of copper

A new method is descibed forthe determination of copper. Fom a suitable solution, copper is extracted as its 8-hydroxyquinaldine complex into chloroform. The solution is diluted with an equal volume of benzene and passed through an activated alumina chromatographic column, whereupon all the 8-hydroxyquinaldates, except that of chromium, are adsorbed. Copper is eluted completely by developing the column with a 0.5% solution of 8-hydroxyquinaldine in that solvent mixture. The optical density of the cluate is measured at 400 mμ with respect to the solvent. Iron, molybdenum and vanadium interfere, but interference due to iron and molybdenum is readily overcome by a simple preliminary treatmont.     

The 7-Iodo-8-Quinolinol-5-Sulfonic Acid Chelates of Some Rare Earth Metal Ions

The dissociation constants of 7-iodo-8-quinolinol-5-sulfonic acid and the formation constants of it's chelates with La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III) and Lu(III) have been determined potentiometrically in 1:1 v/v dioxane-water medium at 25±0.1°C and at an ionic strength of 1 with respect to sodium chloride.     

Precipitation of copper 8-hydroxyquinaldate from homogeneous solution

Copper can be precipitated quantitatively, over a wide range of pH, by 8-hydroxyquinaldine produced from the hydrolysis of 8-acetoxyquinaldine. The copper 8-hydroxyquinaldate can be weighed as either the monohydrate or the anhydrous dichelate. Differences in the appropriate pH conditions, between the PFHS and conventional precipitation methods, and between thorium and copper precipitations from homogeneous solution, are accounted for.     

Chelate von Chinolin-8-ol-Derivaten. IV [1]

Chelates of 8-Quinolinol Derivatives. IV. Properties, Adduct Formation, and Extraction of Nickel(II) Chelates with n-Alkyl-8-quinolinols Containing Long Chain Substituents The nickel(II) chelates of 5- and 7-nonyl-, 5- and 7-decyl- and 5-chlor-7-decyl-8-quinolinol as well as adducts with water and ammonia were synthesized and characterized by spectra and magnetic moments. The existence of associated forms was concluded. To characterize the influence of substituents the stability and composition of pyridine adducts in solution were determined. Finally the extraction of nickel(II) was studied, and a comparison of extraction data with acid and coordination stability constants was made in the case of the isomeric nonyl-8-quinolinols.     

Chelate von Chinolin-8-ol-Derivaten. VIII. Säure- und Komplexstabilitätskonstanten alkyl- bzw. alkenylsubstituierter Chinolin-8-ole

Chelates of 8-Quinolinol Derivatives. VIII. Acid and Complex Stability Constants of Alkyl and Alkenyl Substituted 8-Quinolinols For a series of 7-substituted alkyl and alkenyl 8-quinolinols as well as 2-, 5-, and 7-methyl-8-quinolinols the acid constants and the stability constants of the nickel and zinc chelates were determined potentiometrically in 75 vol-% dioxane-water mixture. Methyl groups, as expected, increase the basicity of both donor atoms of the 8-quinolinols, whereas alkyl substituents in 7-position cause a decrease in basicity of the quinoline N-atom. The influence of substituents on the complex stability is only small.     

Quantitative dünnschicht-chromatographische Bestimmung einiger 8-Hydroxychinolin- und 8-Hydroxychinaldin-Derivate

A method is described allowing direct quantitative determination of 8-hydroxyquinoline and 8-hydroxyquinaldine derivatives with a chromatogram spectrophotometer after development on silicagel plates. In contrast to untreated plates, pretreatment of the plates with complexing agents like ethylene-diamine-tetraacetic acid, diethylenetriamine-pentaacetic acid, or triethylenetetramine-hexaacetic acid, results in formation by the compounds of round areals which are suitable for quantitative measurement. This method proved also valuable for the quantitative measurement of the active contents of pharmaceutical formulations, like tablets or ointments. It is reproducible with a maximal relative standard deviation of ± 3.4%.     

Komplexbildung und extraktion von kupfer und eisen sowie gallium mit isomeren langkettigen alkylchinolin-8-olenComplex formation and liquid-liquid extraction of copper,iron and gallium with isomeric long-chain alkylquinolin-8-ols

The extraction of copper(II) and iron(III) with the 5-nonyl-, 5- and 7-decyl- and 5-chloro-7-decyl derivatives of quinolin-8-ol was studied with chloroform, benzene or toluene as the organic solvent. Isomeric extractants show only small differences and are very suitable for the extraction of copper and its separation from iron, similarly to Kelex 100 (7-dodecenylquinolin-8-ol). With these derivatives log K_ex values are ?5.18 to ?6.08 for iron(III) with pH_0,5 = 4.5 to 5, whereas log K_ex values are 1.54 to 1.82 for copper(II) with pH_0,5 ≈ 1.35. The chelates of copper, iron and gallium with isomeric ligands, isolated as the solids, have characteristic differences in melting points and solubilities. To extract gallium from alkalin solution, only 7-alkyl-8-quinolinols proved as favourable.     

5-Methyl-7-nitroso-8-hydroxyquinoline and its sensitivity and selectivity towards certain metallic ions

5-Methyl-7-nitroso-8-hydroxyquinoline (5-methyl-7-nitroso-oxine), hitherto undescribed, has been prepared and tested for its sensitivity and selectivity towards various metallic ions at differing pH's. The metals tested include cadmium, ferrous and ferric iron, mercurous and mercuric mercury, lead, nickel, cobalt, thallous thallium, cerous and cerie cerium, copper, chromium, aluminium, zinc, magnesium, vanadium (as vanadate) and gallium. This reagent is comparatively “unsclective” in that it chelates with all the above metals under the conditions employed, and therefore closely follows the behaviour of the parent compound, 8-hydroxyquinoline (oxine). Its average sensitivity is somewhat greater than that of the parent compound, and it shows its greatest sensitivity with. divalent mercury.     

Dissociation Constants and Chelate Stability Constants of Some Dihalogenated 8-Hydroxyquinaldines

The acid dissociation constants of dihalogenated 8-hydroxyquinaldines and the stability constants of their chelates with Zn[II], Ni[II], Co[II], Pb[II], Cd[II], Mn[II], and Mg[II] have been determined. The Calvin-Bjerrum potentiometric titration technique was used in studying the behavior of these substances. The order of decreasing stability of the metal chelates Zn, Nc>Co>Pb>Cd>Mn>Mg is similar to the stability sequence generally obtained for divalent metals, and the order of decreasing stability of dihalogenated 8-hydroxyquinaldines to form the metal chelates with metal ions is I>Br>Cl. Spot test reactions of dihalogenated 8-hydroxyquinaldines and 8-hydroxyquinolines with the metal ions also have been investigated.     

Stability and distribution constants of thallium(I) dithiocarbamates

Stability and distribution constants of thallium(I) chelates with diethyl-(I), pyrrolidine- (II), piperidine- (III), phenylethyl- (IV) and methylphenylethyldithiocarbamate (V) have been radiometrically determined using ion-exchange and solvent extraction methods. Stability constants of individual chelates do not change considerably, however, the distribution constants of neutral chelates increase in the order II<IV<IIII<V.     

The synthesis of a series of 7-amino-1-cyclopropyl-8-fluoro-1,4-dihydro-4-oxo-1,6-naphthyridine-3-carboxylic acids as potential antibacterial agents

A series of 7-amino-1-cyclopropyl-1,4-dihydro-8-fluoro-4-oxo-1,6-naphthyridine-3-carboxylic acids has been prepared and evaluated for antibacterial activity. These compounds were prepared by the displacement of the chloro substituent from 7-chloro-1-cyclopropyl-1,4-dihydro-8-fluoro-4-oxo-1,6-naphthyridine-3-carboxylic acid employing the requisite nitrogen nucleophile to produce the title compounds. The naphthyridine acid was synthesized in ten steps from ethyl 2,4-dihydroxy-3-nitro-5-pyridinecarboxylate. The key step in the sequence was a Schiemann reaction carried out using the hexafluorophosphate salt of the diazonium ion derived from ethyl 3-amino-2,4-dichloro-5-pyridinecarboxylate.     

Effect of Dimethyl Sulfoxide and Dimethylformamide on the Stability of 4-Halo-8-quinolinols

Summary. Polyhalo-8-quinolinols with chlorine or bromine in position 4 were not stable in DMSO or DMF. The degradation product from 4,5-dichloro-8-quinolinol was 5-chloro-4,8-quinolindiol and the major product from 4,5-dibromo-8-quinolinol was 3,5-dibromo-4,8-quinolindiol. 4,5,7-Trichloro- and 4,5,7-tribromo-8-quinolinols yielded similar hydrolytic products, and for the bromo compound, a rebrominated product in DMSO. In DMF rebromination did not occur. In pyridine-d₅ these reactions did not take place, indicating a special ability of DMSO and DMF to cause such hydrolysis at position 4 of 4-halo-8-quinolinols.Received December 13, 2002; accepted January 7, 2003 Published online June 23, 2003     

SYNTHESIS AND APPLICATION OF SOME NEW 5-SULPHONYL-N-HETEROCYCLO-8-HYDROXYQUINOLINE DERIVATIVES AS POTENTIAL DRUGS

Abstract

Some new sulphonyl-N-heterocyclo-8-hydroxy quinolines have been synthesised by the reaction of 8-hydroxyquinoline-5-sulphonyl hydrazide with different active methylene compounds. The pyrazole, pyrazoline, pyrazolidine and pyridazine derivatives were reacted with some metal cations to give the corresponding chelates. All synthesized compounds have been screened in vitro for their biological activities.