Preparation and Antifungal Activity of 3-Iodo- and 6-Iodo-8-quinolinols

Summary.  3-Iodo- and 6-Iodo-8-quinolinols were prepared and tested against six fungi: Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes in Sabouraud dextrose broth. A comparison with the previously known 5-iodo- and 7-iodo-8-quinolinols showed that the 6-iodo isomer was the most active. Corresponding author. E-mail: clarke@fordham.edu Received May 15, 2002; accepted June 11, 2002     

Preparation and fungitoxicity of 3-bromo-6-chloro- and 6-bromo-3-chloro-8-quinolinols

Summary 3-Bromo-6-chloro- and 6-bromo-3-chloro-8-nitro, -8-amino-, and -8-hydroxyquinolines along with 3-bromo- and 3-chloroquinolin-6,8-diols were prepared and tested for antifungal activity against six fungi (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, Trichophyton mentagrophytes) inSabouraud dextrose broth. Compounds with chlorine in the 3 position were generally more fungitoxic than the corresponding analogues with bromine. 6-Bromo-3-chloro-8-quinolinol inhibited four fungi at levels below 1 µg/ml andA. niger andM. cirinelloides at 2 µg/ml each.

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Synthese und Fungitoxizität von 3-Brom-6-chlor- und 6-Brom-3-chlor-8-chinolinolen

Zusammenfassung 3-Brom-6-chlor- und 6-Brom-3-chlor-8-nitro-, -8-amino- und -8-hydroxychinoline sowie 3-Brom- und 3-Chlorchinolin-6,8-diole wurden hergestellt und gegen sechs Pilzstämme (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, Trichophyton mentagrophytes) inSabouraud-Dextrosenährmedium auf lhre fungizide Aktivität untersucht. Verbindungen mit Chlor in Position 3 sind durchwegs fungitoxischer als die entsprechenden Bromanalogen. 6-Brom-3-chlor-8-chinolinol hemmt das Wachstum von vier Pilzen bei Konzentrationen unter 1 µg/ml und das vonA. niger undM. cirinelloides bei einer Konzentration von jeweils 2 µg/ml.

     

Preparation and Fungitoxicity of Some Dibromo-8-quinolinols

Summary.  2,5-, 3,5-, 3,6-, 3,7-, 4,5-, 5,6-, 5,7-, and 6,7-dibromo-8-quinolinols were prepared and tested against six fungi (Aspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. Most of the compounds were strongly antifungal, inhibiting five of the fungi below 1μg/cm³, but were somewhat less fungitoxic than the corresponding chloro analogues. M. cirinelloides was not inhibited by any of the compounds except 4,5-dibromo-8-quinolinol. This high level of fungitoxicity is attributed to intramolecular synergism. Received December 28, 2000. Accepted (revised) February 3, 2001     

Preparation and fungitoxicity of 3,6-dichloro-and 3,6-dibromo-8-quinolinols

Summary 3,6-Dichloro- and 3,6-dibromo-8-quinolinols were prepared by direct halogenation of 8-nitroquinoline by N-halosuccinimide in acetic acid or by halogenation of the corresponding 6-halo-8-nitroquinoline prepared via aSkraup reaction. The nitro group was reduced to amino and the amine was hydrolyzed to the phenol in 70% sulfuric acid at 220°C. The fungitoxicity of 3,6-dichloro- and 3,6-dibromo-8-quinolinols, as well as intermediates in their preparation, againstAspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, andMucor cirinelloides was determined. 3,6-dichloro-8-quinolinol is the most fungitoxic analogue of this class of compounds observed to date.

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Herstellung und Fungitoxizität von 3,6-Dichlor- und 3,6-Dibrom-8-chinolinen

Zusammenfassung 3,6-Dichlor- und 3,6-Dibrom-8-chinoline wurden durch direkte Halogenierung von 8-Nitrochinolin mit N-Halogensuccinimid in Essigsäure oder durch Halogenierung der entsprechenden nachSkraup synthetisierten 6-Halogen-8-nitrochinoline hergestellt. Die Nitrogruppe wurde zum Amin reduziert und die Aminofunktion in 70% iger Schwefelsäure bei 220°C zum Phenol hydrolysiert. Die Fungitoxizität der 3,6-Dichlor- und 3,6-Dibrom-8-chinoline und jene der bei ihrer Herstellung auftretenden Zwischenstufen gegenAspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride undMucor cirinelloides wurde bestimmt. 3,6-Dichlor-8-chinolin ist der derzeit stärkste bekannte fungitoxische Vertreter dieser Substanzklasse.

     

Thermal fragmentations of nitrated 8-quinolinols

8-Quinolinols which are substituted in the aromatic nucleus by nitro-, chloro-, or by sulfonic acid groups underwent a neat thermal fragmentation upon heating in 75% nitric acid as reaction medium yielding 2,3-dicarboxypyridinium nitrate. The scope and the mechanism of these reactions are discussed.     

The synthesis of substituted 8-quinolinols

2-Isopropyl-8-quinolinol was prepared by alkylation of 8-methoxyquinoline followed by demethylation. The 7-isopropyl-8-quinolinol was prepared in three steps from o-isopropylphenol. The reaction of 5-chloromethyl-8-quinolinol hydrochloride with alcohols, amines, ethylene glycols and ether-alcohols gave the corresponding 5-substituted derivatives of 8-quinolinol.     

Electrochemical study of solvent extraction with 8-quinolinols as complexing agent-I. Distribution behavior of 8-quinolinols

The distribution behavior of 8-quinolinols (HQ) in organic and acidic aqueous solutions (or alkaline solutions) was electrochemically examined by current scan polarography and chronopotentiometry. It follows from the results that the half wave potential of the observed polarographic waves, corresponding to the Faradaic transfer of quinolinolium ions (or oxinate ions) formed in the aqueous solution after distribution of quinolinols is dependent on the dissociation constant of H(2)Q(+) (or HQ) and the pH of the aqueous solution, but independent of the distribution constant of 8-quinolinols.     

Organotin complexes of 5-arylazo-8-quinolinols

5-Phenylazo-8-quinolinol (LH) forms di/tri-organotin complexes similar to the well-known organotin oxinates, but 5-(2′-carboxyphenylazo)-8-quinolinol (L′HH′) forms three classes, viz., the carboxylate derivatives of the type R₃SnL′H, the quinolinolates of the type R₂Sn(L′SnR^′₃)₂ and R₃SnL′SnR^′₃. The carboxylates, R₃SnL′H, are 5-coordinate complexes similar to other triorganotin arylazobenzoates and the quinolinolates, R₂Sn (L′H′)₂, closely resemble the corresponding organotin oxinates. Unlike the oxinates, R₂Sn(L′H′)₂ type complexes can, be made water soluble by treatment with aqueous NaHCO₃ whereby R₂Sn(L′Na)₂ type complexes are formed. The binuclear complexes of the type R₂Sn(L′SnR^′₃)₂ contain 5- and 6-coordinate organotin groups in the same ligand.     

Improved syntheses of some monochloro- and monobromo-8-quinolinols

Summary Procedures were developed for the preparation of the 2-, 3-, 4-, and 6-monosubstituted chloro and bromo 8-quinolinols which afforded greater yields and/or reduced the number of steps in the preparation. 100 MHz¹H-NMR spectra for the 12 possible monochloro and monobromo analogues are given.

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Verbesserte Synthese von Monochlor- und Monobrom-8-chinolinolen

Zusammenfassung Es wurden Verfahren entwickelt, um 2-, 3-, 4- und 6-Chlor bzw. -Brom-8-chinolinole in besseren Ausbeuten und/oder bei reduzierter Anzahl von Synthesestufen herzustellen. Die¹H-NMR-Spektren der 12 möglichen Monochlor- und Monobromverbindungen werden angegeben.

     

5- and 7-substituted 2-methyl-8-quinolinols

The synthesis and characterization of the 5- and 7-monosubstituted 2-methyl-8-quinolinols where the substituents are fluorine, chlorine, bromine, iodine, nitro, amino, and sulfonic acid groups were carried out. The bischelates with copper(II) of those ligands containing hydrogen, fluorine, chlorine, bromine, iodine, and nitro are also reported.     

Preparation of Ethyl 5-Iodo-1H-indole- 2-carboxylate

Abstract

A facile, two step procedure for the preparation of ethyl 5-iodo-1H-indole-2-carboxylate (1) from commercially available ethyl 1H-indole-2-carboxylate is described herein, employing a regioselective C3, C5-bisiodination followed by zinc-mediated C3-dehalogenation.     

Preparation and physical properties of BiMo6S8 and SbMo6S8

The compounds Me₁Mo₆S₈ (Me = Bi, Sb) were prepared by low-temperature diffusion of Bi and Sb into the binary phase Mo₆S₈. The homogeneity range of the ternary elements is very narrow and centered about Me = 1.0, implying that the ternary metal is located at the origin position of the rhombohedral unit cell. The observed lattice parameters (BiMo₆S₈, a_h = 9.194, c_h = 11.325; SbMo₆S₈, a_h = 9.122, c_h = 11.282) are consistent with this hypothesis and suggest that these atoms enter the structure as trivalent cations. No superconducting transition is observed for these materials above 2 K. A small temperature-independent paramagnetism is present in the magnetic susceptibility of these compounds. The magnitude of this paramagnetism is less than that found in other ternary molybdenum chalcogenides with trivalent cations, suggesting that a reduced density of states is responsible for the observed lack of superconductivity. Attempts to prepare MeMo₆(S_1−xSe_x)₈ (Me = Sb and Bi) with x > 0 failed to yield ternary phases, instead producing mixtures of the unreacted ternary metal and the corresponding binary phase.     

Preparation of 6-Fluoro-8-quinolinol and Related 6-Fluoroquinolines

 6-Fluoro-8-quinolinol was prepared from 2-amino-5-fluorophenol by a Skraup synthesis. No synergism was observed between 5-fluoro- and 6-fluoro-8-quinolinols or between 6-fluoro- and 7-fluoro-8-quinolinols against any of the six fungi in our test system (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. Unlike the fluoro-8-quinolinols, the 8-quinolinols comparably substituted with chlorine or bromine did form synergistic mixtures. This is attributed to steric factors.     

Preparation of 6-Fluoro-8-quinolinol and Related 6-Fluoroquinolines

Summary.  6-Fluoro-8-quinolinol was prepared from 2-amino-5-fluorophenol by a Skraup synthesis. No synergism was observed between 5-fluoro- and 6-fluoro-8-quinolinols or between 6-fluoro- and 7-fluoro-8-quinolinols against any of the six fungi in our test system (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. Unlike the fluoro-8-quinolinols, the 8-quinolinols comparably substituted with chlorine or bromine did form synergistic mixtures. This is attributed to steric factors. Corresponding author. E-mail: clarke@fordham.edu Received May 23, 2002; accepted May 29, 2002     

1-甲基-3-二氟甲基-4-吡唑酰胺类衍生物的合成及其抑菌活性

结合吡噻菌胺和呋吡菌胺的结构特点,以3,4-亚甲二氧基苯酚和1,2-亚甲二氧基苯为原料合成了7个新型1-甲基-3-二氟甲基-4-吡唑甲酰胺类化合物(6a～6g),其结构经1H NMR,IR和MS表征.初步生物活性测试结果表明,6a对所有供试菌均有一定的抑菌活性,6b和6d对番茄灰霉菌有较好的抑菌活性.