1127-45-3

Usage

Uses

Used in Chemical Research:
8-Hydroxyquinoline-N-oxide is used as a research compound for studying its mutagenic activity and its interactions with metals like palladium(II) and gold(III). Its unique ability to form complexes with these metals makes it a valuable tool in understanding chemical bonding and reactivity.
Used in Environmental Monitoring:
As a toxicant that can suppress the luminescence of Photobacterium phosphoreum, 8-Hydroxyquinoline-N-oxide can be utilized in environmental monitoring applications to detect and assess the presence of toxic substances in aquatic ecosystems.
Used in Pharmaceutical Industry:
8-Hydroxyquinoline-N-oxide, due to its mutagenic properties, can be employed in the pharmaceutical industry for the development of new drugs targeting specific genetic mutations. Its interaction with metals may also be leveraged in the design of metal-based therapeutic agents.
Used in Material Science:
The formation of metal chelates with palladium(II) and gold(III) suggests potential applications in material science, where 8-Hydroxyquinoline-N-oxide could be used to develop new materials with unique properties, such as catalysts or sensors.

Synthesis

8-hydroxyquinoline-N-oxide was synthesized from 8-hydroxyquinoline. A stirred solution of 8-hydroxyquinoline (25.00 g, 172.2 mmol) in 550 ml of CHCl3?was cooled to 0° C., and 3 -chloroperoxybenzoic acid (40.00 g, 80% Tech. grade *0.231 mmol=0.185 mmol) was added slowly over 3 minutes. The solution was kept at 0° C. and stirred for 3 hours. During this period, the 3-chlorobenzoic acid byproduct precipitated. The 3-chlorobenzoic acid was removed by filtration and the orange filtrate was concentrated to dryness and the remaining solid was triturated with 2% NH40?H (2*200 ml). The solid was isolated on a frit and washed with H2O.

InChI:InChI=1/C9H7NO2/c11-8-5-1-3-7-4-2-6-10(12)9(7)8/h1-6,11H

Upstream product

• 79-21-0 peracetic acid 
• 148-24-3 8-quinolinol 
• 93-59-4 Perbenzoic acid 
• 2311-91-3 monoperoxyphthalic acid 
• 64741-01-1 m-chloroperoxybenzoic acid 

Downstream Products

• 63319-28-8 1-oxy-5-phenylazo-quinolin-8-ol 
• 15450-72-3 2-hydroxyquinolin-8-yl acetate 
• 21168-37-6 5-nitro-8-hydroxyquinoline-N-oxide 
• 21168-36-5 5,7-dinitro-8-hydroxyquinoline-N-oxide 
• 85843-12-5 8-hydroxy-7-nitroquinoline N-oxide 
• 15450-72-3 2-oxo-1,2-dihydroquinolin-8-yl acetate 
• 721396-93-6 2-[2-(4-n-butylphenyl)-6-(6-methylpyridin-2-yl)-pyrimidin-4-yl]-quinolin-8-ol 
• 874357-44-5 2-[2-(4-n-butylphenyl)-6-(6-methylpyridin-2-yl)-pyrimidin-4-yl]-quinolin-8-yl acetate 
• 15450-76-7 quinoline-2,8-diol 
• 31568-91-9 2-chloroquinolin-8-ol 
• 6759-79-1 8-hydroxyquinoline-2-carboxamide 
• 21141-35-5 8-methoxyquinoline-2-carboxylic acid 
• 1571-30-8 8-hydroxy-quinoline-2-carboxylic acid 
• 70125-16-5 2-amino-8-quinolinol 

Relevant academic research and scientific papers

Blue and white light electroluminescence in a multilayer OLED using a new aluminium complex

Synthesis, structure, optical absorption, emission and electroluminescence properties of a new blue emitting Al complex, namely, bis-(2-amino-8- hydroxyquinolinato), acetylacetonato Al(III) are reported. Multilayer OLED using the Al complex showed blue emission at 465 nm, maximum brightness of ～ 425 cd/m2 and maximum current efficiency of 0.16 cd/A. Another multilayer OLED using the Al complex doped with phosphorescent Ir complex showed 'white' light emission, CIE coordinate (0.41, 0.35), maximum brightness of ～ 970 cd/m2 and maximum current efficiency of 0.53 cd/A. Indian Academy of Sciences.

Low-dimensional compounds containing bioactive ligands. Part XVI: Halogenated derivatives of 8-quinolinol N-oxides and their copper(II) complexes

Four N-oxides, 8-quinolinol N-oxide (8-HQNO), 5,7-dichloro-8-quinolinol N-oxide (HdClQNO), 5,7-dibromo-8-quinolinol N-oxide (HdBrQNO) and 7-iodo-8-quinolinol N-oxide (HIQNO) as well as their six copper complexes, CuCl2(8-HQNO)2(H2O) (1), CuCl2(HdClQNO)2(H2O)2 (2), Cu(dClQNO)2(CHCl3) (3), Cu(dClQNO)2(H2O) (4), {[Cu(dBrQNO)2]?2H2O}n (5) and CuCl2(HIQNO)2(H2O)4 (6) were synthesised as possible anticancer agents. Crystal structures of N-oxides contain planar molecules held together via hydrogen bonds involving oxygen atoms of N-oxide groups as acceptors. Crystal structure of 5 represents the first structure of a copper(II) complex with an N-oxide ligand derived from 8-HQNO and is formed by infinite chains. In the chain, the Cu(II) atom coordinates to six oxygen atoms from two bidentate chelating dBrQNO ligands occupying apexes of elongated tetragonal bipyramid with bridging oxygen atoms of N-oxide groups in axial positions. Antiproliferative activity of prepared N-oxides as well as their complexes was studied using in vitro MTT assay against the MDA-MB-231, HCT-116 and A549 cancer cell lines and their selectivity was verified on MSCs cells. Among the tested cancer cell lines, A549 and MDA-MB-231 cells were the most sensitive to the tested complexes. Complex 1 showed the highest cytotoxicity against both tumor cell lines. At concentration, which could be tested in animal models, 1 induced cell death in more than 50% of cancer cells and in 20% of MSCs indicating its selectivity.

SYNTHESIS OF LAVENDAMYCIN

A regiospecific and convergent synthesis of Lavendamycin (1) starting from 8-hydroxyquinoline and indole via Bischler-Napieralski cyclisation is described.

Heterocyclic Aromatic N-Oxidation in the Biosynthesis of Phenazine Antibiotics from Lysobacter antibioticus

Heterocyclic aromatic N-oxides often have potent biological activities, but the mechanism for aromatic N-oxidation is unclear. Six phenazine antibiotics were isolated from Lysobacter antibioticus OH13. A 10 gene cluster was identified for phenazine biosynthesis. Mutation of LaPhzNO1 abolished all N-oxides, while non-oxides markedly increased. LaPhzNO1 is homologous to Baeyer-Villiger flavoproteins but was shown to catazlye phenazine N-oxidation. LaPhzNO1 and LaPhzS together converted phenazine 1,6-dicarboxylic acid to 1,6-dihydroxyphenazine N5,N10-dioxide. LaPhzNO1 also catalyzed N-oxidation of 8-hydroxyquinoline.

Oxo-rhenium(V) complexes with 8-hydroxyquinoline derivatives

Compounds of the types ReOCl2(L)(PPh3) and ReOCl(L)2 were prepared by reacting ReOCl3(PPh 3)2 with 8-hydroxyquinoline (HL) and its 2-methyl, 2-chloro, 5-chloro, 5-nitro, 5,7-dichloro, 5,7-dibromo, and 5,7-diiodo derivatives. With the bulky 2-phenyl-8-hydroxyquinoline, only ReOCl 2(L)(PPh3) could be isolated, whereas the still bulkier 2-tert-butyl derivative did not react. For ReOCl2(L)(PPh 3), the coordination of the quinoline oxygen trans to the Re=O bond and the cis-dichloro arrangement in the equatorial plane were established from crystallographic studies on the 2-chloro and the 5,7-dibromo complexes. From the combined data for these various derivatives, the 1H NMR signals could be fully assigned. With both series of compounds, a complex d-d absorption pattern is observed in the visible spectra, corresponding to the excitation of a d electron from the interaxial d orbital in the equatorial plane to the empty dxz and dyz orbitals, which are inequivalent in these low-symmetry systems. Deconvolution revealed the presence of two very weak low-energy components (～10 000 and ～12 000 cm-1), which are assigned to the two expected singlet-triplet transitions, whereas two stronger bands at higher energy (～14 000 and ～17 000 cm-1) originate from the two singlet-singlet transitions. These bands are not substantially displaced by substitution on the 8-hydroxyquinoline rings.

Synthesis and evaluation of radioiodinated 1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}piperidin-4-amine derivatives for platelet-derived growth factor receptor β (PDGFRβ) imaging

Platelet-derived growth factor receptor β (PDGFRβ) is a transmembrane tyrosine kinase receptor and it is upregulated in various malignant tumors. Radiolabeled PDGFRβ inhibitors can be a convenient tool for the imaging of tumors overexpressing PDGFRβ. In this study, [125I]-1-{5-iodo-2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinoline-8-yl}piperidin-4-amine ([125I]IIQP) and [125I]-N-3-iodobenzoyl-1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}-piperidin-4-amine ([125I]IB-IQP) were designed and synthesized, and their potential as PDGFRβ imaging agents was evaluated. In cellular uptake experiments, [125I]IIQP and [125I]IB-IQP showed higher uptake by PDGFRβ-positive cells than by PDGFRβ-negative cells, and the uptake in PDGFRβ-positive cells was inhibited by co-culture with PDGFRβ ligands. The biodistribution of both radiotracers in normal mice exhibited hepatobiliary excretion as the main route. In mice inoculated with BxPC3-luc (PDGFRβ-positive), the tumor uptake of radioactivity at 1 h after the injection of [125I]IIQP was significantly higher than that after the injection of [125I]IB-IQP. These results indicated that [125I]IIQP can be a suitable PDGFRβ imaging agent. However, further modification of its structure will be required to obtain a more appropriate PDGFRβ-targeted imaging agent with a higher signal/noise ratio.

Palladium-catalyzed alkenylation of quinoline-N-oxides via C-H activation under external-oxidant-free conditions

(Chemical Equation Presented) The direct cross-coupling of quinoline-N-oxides with olefin derivatives has been realized using palladium acetate as the catalyst in the absence of external ligand and oxidant to give the corresponding 2-alkenylated quinolines and 1-alkenylated isoquinolines chemo- and regioselectively in 27-95% yield. The catalytic process is proposed to proceed via direct C-H bond activation of the quinoline-N-oxide with Pd(OAc)2 followed by Heck coupling with the olefin. The resultant N-oxide of the alkenylated quinoline can oxidize the reduced Pd(0) to regenerate the Pd(II) active species and simultaneously release the 2-alkenylated quinoline without using any external oxidants and reductants.

Site-specific tagging proteins with a rigid, small and stable transition metal chelator, 8-hydroxyquinoline, for paramagnetic NMR analysis

Design of a paramagnetic metal binding motif in a protein is a valuable way for understanding the function, dynamics and interactions of a protein by paramagnetic NMR spectroscopy. Several strategies have been proposed to site-specifically tag proteins with paramagnetic lanthanide ions. Here we report a simple approach of engineering a transition metal binding motif via site-specific labelling of a protein with 2-vinyl-8-hydroxyquinoline (2V-8HQ). The protein-2V-8HQ adduct forms a stable complex with transition metal ions, Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The paramagnetic effects generated by these transition metal ions were evaluated by NMR spectroscopy. We show that 2V-8HQ is a rigid and stable transition metal binding tag. The coordination of the metal ion can be assisted by protein sidechains. More importantly, tunable paramagnetic tensors are simply obtained in an α-helix that possesses solvent exposed residues in positions i and i + 3, where i is the residue to be mutated to cysteine, i + 3 is Gln or Glu or i - 4 is His. The coordination of a sidechain carboxylate/amide or imidazole to cobalt(II) results in different structural geometries, leading to different paramagnetic tensors as shown by experimental data.

SYNTHESIS OF A NOVEL HEXADENTATE CHELATING AGENT BASED ON 8-HYDROXYQUINOLINE

A new hexadentate chelator was synthesized by the functionalization of 8-hydroxyquinoline to its 2-carboxy-N-hydroxysuccinimidyl ester and a subsequent condensation with tris(2-aminoethyl)amine to give tris-N-(2-aminoethyl-)amine.This molecule is a siderophore analog with a non-naturally occurring binding unit comprising a combination of both oxygen and nitrogen donor atoms.

First safe and practical synthesis of 2-amino-8-hydroxyquinoline

The first safe and efficient synthesis of the important building block 2-amino-8-hydroxyquinoline (1) is described. Starting from the readily available N-oxide 3 of the cheap bulk chemical 8-hydroxyquinoline (2), the target compound is obtained in a two-step one pot procedure in good overall yield (53-66%) and purity (>98%) on a kilogram scale without chromatography.