8-Quinolinol, 7-nitro- - ≥97% , CAS No.18472-01-0

CAS: 18472-01-0 Cat. No.: Q1019314 Formula: C₉H₆N₂O₃ Peso molecolare: 190.160

GRADE & PURITY ≥97%

Storage

Room temperature

Specifications

Specifiche e purezza

≥97%

Condizioni di conservazione di stoccaggio

Room temperature

Purezza

≥97%

Nomi e identificatori

Sorrisi canonici

C1=CC2=C(C(=C(C=C2)[N+](=O)[O-])O)N=C1

IUPAC Name

7-nitroquinolin-8-ol

InChIKey

RPJWQGVDVSVGPQ-UHFFFAOYSA-N

INCHI

1S/C9H6N2O3/c12-9-7(11(13)14)4-3-6-2-1-5-10-8(6)9/h1-5,12H

Peso molecolare

190.160

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organoheterocyclic compounds
    • Classe Quinolines and derivatives
      • Subclass Nitroquinolines and derivatives

• Kingdom: Organic compounds
• Superclass: Organoheterocyclic compounds
• Classe: Quinolines and derivatives
• Subclass: Nitroquinolines and derivatives
• Intermediate Tree Nodes: Not available
• Direct Parent: Nitroquinolines and derivatives
• Alternative Parents: 8-hydroxyquinolines Nitroaromatic compounds 1-hydroxy-4-unsubstituted benzenoids Pyridines and derivatives Heteroaromatic compounds Propargyl-type 1,3-dipolar organic compounds Organic oxoazanium compounds Azacyclic compounds Organopnictogen compounds Organooxygen compounds Organonitrogen compounds Organic zwitterions Organic oxides Hydrocarbon derivatives
• Molecular Framework: Aromatic heteropolycyclic compounds
• Substituents: Nitroquinoline - 8-hydroxyquinoline - Nitroaromatic compound - 1-hydroxy-4-unsubstituted benzenoid - Pyridine - Benzenoid - Heteroaromatic compound - C-nitro compound - Organic nitro compound - Organic oxoazanium - Azacycle - Organic 1,3-dipolar compound - Propargyl-type 1,3-dipolar organic compound - Allyl-type 1,3-dipolar organic compound - Organic nitrogen compound - Hydrocarbon derivative - Organic zwitterion - Organic oxide - Organooxygen compound - Organonitrogen compound - Organopnictogen compound - Organic oxygen compound - Aromatic heteropolycyclic compound
• Descrizione: This compound belongs to the class of organic compounds known as nitroquinolines and derivatives. These are compounds containing a nitro group attached to a quinoline moiety.
• External Descriptors: Not available

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Proprietà chimiche e fisiche

• Peso molecolare: 190.160 g/mol
• XLogP3: 2.200
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 4
• Rotatable Bond Count: 0
• Exact Mass: 190.038 Da
• Monoisotopic Mass: 190.038 Da
• Topological Polar Surface Area: 78.900 Ų
• Heavy Atom Count: 14
• Formal Charge: 0
• Complexity: 229.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

No vendor-validated bioassay protocols are provided for this SKU. Typical research practices (general guidance) include:

• Stock preparation: dissolve at 10–50 mM in DMSO; vortex and, if needed, warm gently; filter (0.22 µm PTFE) to clarify. Store aliquots.
• Metal-binding assay (UV–vis/fluorescence): prepare buffered solution (e.g., HEPES, pH 7.5–8.5) with ≤1% DMSO; titrate metal salt into ligand; record spectra; fit binding isotherms.
• Synthetic use: follow standard alkylation/acylation or reduction conditions as outlined under Reaction Conditions.

For application-specific, validated procedures, consult the primary literature. This product is for research use only.

Biological Roles

No clinical or therapeutic roles are claimed for this product. The following pertains to research/biochemistry contexts (literature, general):

• Metal ion modulation: 8-hydroxyquinoline scaffolds bind biologically relevant metal ions (e.g., Zn2+, Cu2+, Fe3+). The 7-nitro derivative can be used to modulate metal availability in biochemical assays, probe metal-dependent enzyme activities, or pre-chelate metals for delivery to model systems.
• Spectroscopic probes: metal complexation often alters absorbance/fluorescence, enabling ratiometric or turn-on/off readouts in cell-free systems. The nitro group can impact intersystem crossing and internal charge transfer, tuning photophysics relative to the parent compound.
• Ligand competition studies: useful as a benchmark chelator to evaluate binding affinities versus peptides or small molecules in buffered media, with readout by UV–vis, fluorescence, or ICP-based mass balance.
• Model toxicology/biotransformation: while specific biological effects are not claimed here, nitroaromatic heterocycles can undergo reductive metabolism in some systems; researchers may leverage this reactivity in vitro to study redox processes and conjugation pathways.

Cautions:

• Maintain DMSO or organic cosolvent below levels tolerated by your assay system.
• Control pH and ionic strength to manage ligand ionization and metal speciation.
• Avoid interpreting biological effects as therapeutic outcomes; this product is for research use only.

Buffer Applications

This compound is not a buffering agent and is not typically used to establish or maintain pH. In buffered experiments, it is generally added as a solute (often from a DMSO or alcoholic stock) to pre-made buffers.

Practical notes:

• Choose buffers that do not strongly chelate metals if you are studying metal–ligand interactions (avoid high concentrations of EDTA, citrate, phosphate for certain metals). Good choices include HEPES, MES, or TRIS at minimal concentrations consistent with your assay.
• Maintain organic cosolvent below assay limits to prevent precipitation (common working stocks: 1–10 mM in DMSO; final DMSO ≤1–2% v/v, as tolerated).

Green Alternatives

Greenness can be improved by addressing both the ligand choice and the solvent system used with 7-nitro-8-hydroxyquinoline.

• Ligand considerations (literature, general):

  • If strong chelation is needed without nitroaromatic content, consider parent 8-hydroxyquinoline or bio-derived catechol/salicylate ligands. Tradeoff: selectivity and photophysics differ; nitro substitution often enhances certain spectroscopic responses.
  • For purely aqueous workflows, NTA/IDA-type ligands offer water solubility and lower hazard profiles, but lack the same photoluminescent properties.

• Solvent substitutions: favor low-toxicity, biodegradable solvents where compatible with solubility and reaction needs.

Comparison (general guidance):

| Use case | Conventional | Greener alternative | Trade-offs | |---|---|---|---| | Stock solutions | DMSO | PEG-400, propylene carbonate, ethanol | Lower solubility; potential viscosity issues (PEG-400) | | O-alkylation | DMF/DMSO | Cyrene, propylene carbonate, 2-MeTHF | Base/solubility compatibility must be validated | | Extraction | CHCl3, toluene | EtOAc, 2-MeTHF | Distribution ratios may change; method re-optimization needed | | Hydrogenation solvent | MeOH/EtOH | EtOH (renewable), iPrOH | Kinetics/selectivity may vary |

Notes:

• Always confirm metal salt solubility and phase behavior when changing solvents.
• Waste minimization: recover/recycle organic solvents when possible; use microscale extraction cartridges to reduce volumes.

Pharmaceutical Uses

No pharmaceutical or clinical uses are claimed. This product is provided strictly for research use only.

Formulation-related research contexts (literature, general):

• Analytical reagent: used in method development for metal assay workflows that may support pharmaceutical quality control (e.g., trace metal determinations via chelation and spectrophotometry/fluorimetry).
• Excipient status: there is no common pharmacopeial excipient monograph specific to 7-nitro-8-hydroxyquinoline. If exploring formulation research, confirm acceptability and impurity profiles internally; this compound is primarily an analytical/synthetic reagent in R&D settings.
• Compatibility: may interact with metal-containing actives or excipients due to chelation; evaluate interactions during preformulation research.

Regulatory note: for any work impacting GMP environments, source a defined grade with full CoA and ensure method suitability/validation per ICH/USP where applicable.

Physical Properties

Item-specific physicochemical specifications (e.g., exact mp, residual metals, water, UV cutoff) are not provided in the product data.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point (literature): typically reported in the low 200s °C range for crystalline 7-nitro-8-hydroxyquinoline; consult primary references/SDS for exact values appropriate to your lot.
• Boiling point: not applicable (decomposes before boil under ambient pressure; literature guidance only).
• Density: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (literature, qualitative):
  • Water: very sparingly soluble at neutral pH; increased apparent solubility upon deprotonation (basic media) or in presence of metal ions (chelation).
  • Organic: soluble in polar aprotic solvents (e.g., DMSO, DMF, NMP) and in alcohols/acetone to varying degrees; limited solubility in alkanes.
• pKa (phenolic OH, literature): expected to be slightly lower (more acidic) than 8-hydroxyquinoline due to the 7-nitro substituent; consult literature for numerical values.
• logP/logD: Not specified for this item; refer to CoA/Spec Sheet.
• UV–vis (literature, qualitative): strong π–π* absorbance in near-UV; bathochromic shifts upon metal complexation are common for 8-hydroxyquinoline derivatives.

Important: treat all numerical property values as literature guidance only unless a CoA/Spec Sheet for this SKU provides item-specific specifications.

Quality and Grades

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• UV, metal content, water/peroxide limits: Not specified for this item; refer to CoA/Spec Sheet.

Interpretation and implications (general guidance):

• For applications in metal complexation/analysis or fluorescence sensing, trace metal background and UV-absorbing impurities can be critical. If your workflow is sensitive (e.g., analytical photometry, fluorimetry), request a high-purity grade with documented low metal background and a UV–vis profile.
• For synthetic use, typical organic synthesis grade is often adequate. If using as a ligand precursor or for stoichiometric chelation, ensure moisture content and inorganic residues are controlled to avoid complexation competition.
• Stabilizers: none are indicated for this item. If your application is air/light sensitive (e.g., photophysical measurements), consider storing under inert atmosphere or amber conditions even in the absence of a stabilizer.

Documentation:

• For lot-specific data (assay, residual solvents, LC/HPLC area %, metal screening, particle size), consult the CoA/Spec Sheet associated with SKU Q1019314.

Reaction and Applications

This compound is a classic N,O-bidentate ligand scaffold with electronic modulation from a 7-nitro substituent. Representative research applications include (literature, general):

• Metal chelation and sensing: forms stable 1:1 or 1:2 chelates with many transition metals (e.g., Al3+, Zn2+, Cu2+, Ni2+). The 7-nitro group can tune acidity and photophysics relative to 8-hydroxyquinoline, enabling selective spectro/fluorimetric detection protocols.
• Solvent extraction/analytical separations: as a ligand for metal ion extraction into organic phases; nitro substitution may influence distribution ratios and selectivity in solvent extraction systems.
• Coordination materials: precursor for metal–organic complexes used in catalysis, luminescent materials, and as model systems in coordination chemistry.
• Derivatization platform:
  • Phenolic O-alkylation/O-acylation to access ethers/esters of tailored solubility and donor strength.
  • Nitro group transformations: reduction to the corresponding 7-amino-8-hydroxyquinoline provides a handle for diazotization, coupling, and amide/urea formation.
  • Chelation-assisted transformations: the 8-oxygen/quinoline nitrogen can direct site-selective metalation or C–H activation in advanced synthesis (literature precedents with related 8-hydroxyquinolines).

Practical tips:

• Dry the solid and solvents to minimize adventitious water that competes in metal binding.
• Control pH carefully in aqueous/alcoholic systems: deprotonation of the phenol enhances chelation but may alter spectral baselines.
• For photophysical assays, protect from strong light and use matched blanks due to baseline absorbance of the ligand.

Reaction Conditions

General literature conditions for transformations of 7-nitro-8-hydroxyquinoline (optimize per your system; values are guidance only):

• O-alkylation (to ethers):
  • Base: K2CO3 or Cs2CO3 (2–3 equiv); solvent: DMF, acetone, or acetonitrile.
  • Electrophile: alkyl halide/sulfate (1.2–2.0 equiv).
  • Temperature: 25–60 °C (acetone reflux when needed); time: 2–16 h.
• O-acylation (to esters):
  • Reagents: acyl chloride/anhydride (1.2–1.5 equiv), base (Et3N, pyridine) or DMAP catalysis.
  • Solvent: DCM, THF, or EtOAc; 0–25 °C then warm to RT.
• Nitro reduction (to amine):
  • Catalytic hydrogenation: H2 (1–4 bar) over Pd/C or Raney Ni in EtOH/MeOH; 20–40 °C.
  • Classical: Fe powder/NH4Cl or SnCl2·2H2O in EtOH/HCl; 50–80 °C.
• Metal complexation (spectroscopic prep):
  • Dissolve ligand in EtOH or DMSO; adjust aqueous buffer to mildly basic pH (e.g., pH 7.5–9) to deprotonate phenol; add metal salt stoichiometrically; record spectra promptly.

Workup/purification tips:

• Ethers/esters: aqueous quench, extract with EtOAc, wash thoroughly to remove inorganic salts, silica gel chromatography (hexanes/EtOAc gradient).
• Metal complexes: isolate by precipitation, recrystallization, or preparative HPLC as appropriate; maintain inert conditions if air-sensitive metals are used.

Safety: monitor exotherms during acylation/alkylation; nitro reductions can generate heat and gases—vent properly.

Safety and Handling

GHS classification, signal word, pictograms, and H-statements are not provided in the product data for this SKU; consult the product SDS for authoritative details.

General laboratory safety guidance for nitro-substituted heteroaromatic phenols (informational, not item-specific):

• PPE: lab coat, safety glasses or splash goggles, and appropriate gloves (e.g., nitrile). Handle in a fume hood to minimize inhalation of dust.
• Avoid: inhalation of particulates, skin/eye contact, and ingestion. Wash thoroughly after handling.
• Incompatibilities: strong oxidizers or strong reducing agents (may induce side reactions); strong bases or acids can change solubility/ionization and may promote undesired reactions. Avoid reactive metals unless forming intended metal chelates under controlled conditions.
• Thermal stability: nitroaromatics can decompose on strong heating; avoid grinding-induced dust clouds and ignition sources. Do not distill to dryness.
• Environmental note: metal-chelating ligands can mobilize heavy metals; prevent release to the environment and collect waste appropriately.
• First aid (overview; defer to SDS):
  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Skin/eyes: rinse with water for several minutes; remove contaminated clothing; seek medical attention for persistent irritation.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical attention.

Always follow your institution’s risk assessment and the SDS for this exact product.

Solvent Selection

Solvent choice for 7-nitro-8-hydroxyquinoline typically balances low aqueous solubility with the need to maintain the phenol either neutral (for extraction/complexation) or deprotonated (for reactivity and certain spectroscopic uses).

• Polarity class: moderately polar aromatic heterocycle with a phenolic OH; overall hydrophobic with ionizable site.
• Miscibility/solubility profile (literature, qualitative):
  • Good: DMSO, DMF, NMP, acetone, acetonitrile, ethanol/methanol.
  • Limited: ethyl acetate, toluene (improves upon O-alkylation or metal complexation).
  • Poor: alkanes; water at neutral pH.
• Selection tips:
  • For stock solutions in bioassays or spectroscopy, DMSO is commonly used, diluted into buffer immediately before use to minimize precipitation.
  • For metal complexation studies, alcoholic solvents or buffered aqueous/MeOH mixtures (with controlled pH) facilitate chelate formation and measurement.
  • For O-alkylation/O-acylation, polar aprotic solvents (DMF/DMSO/acetone) with inorganic base (K2CO3, Cs2CO3) are typical.
  • For nitro reduction or downstream derivatization, ethanol/MeOH with catalytic hydrogenation, or mixed solvent with Fe/NH4Cl reductions, are frequently reported.
• Comparison (literature-based):
  • DMSO: highest solubilizing power; may complicate some photophysical reads.
  • MeOH/EtOH: greener, easy removal; lower solubility may limit concentration.
  • ACN/Acetone: good balance of volatility and solvency; watch base compatibility.

Always confirm compatibility with your metal salts, bases, and intended analytical detection.

Storage and Reconstitution

• Storage temperature: Room temperature (per product data). Store tightly closed in a dry place.
• Light/moisture: protect from moisture; consider amber glass to minimize photodegradation in light-sensitive assays.
• Shipping: Not specified for this item; refer to CoA/Spec Sheet.
• Reconstitution/preparation:
  • For stock solutions, dissolve in DMSO, DMF, or alcohols. Typical working stocks: 10–50 mM in DMSO; prepare under dry conditions to limit hydrolysis or adventitious metal binding.
  • If using in aqueous buffers, dilute DMSO stock into buffer with vigorous mixing; maintain final organic cosolvent at assay-tolerated levels to avoid precipitation.
• Freeze–thaw: if storing solutions, aliquot to avoid repeated freeze–thaw cycles; inspect for precipitation or color change before use.
• Stability: Item-specific stability data are not provided. For long-term storage of solutions, prefer −20 °C (amber vials, inert headspace) and verify concentration periodically by UV–vis or gravimetry.

Always refer to the product’s CoA/Spec Sheet and SDS for lot-specific guidance and stability information.

Research Use Note: For research use only.

Structure and Identity

8-Quinolinol, 7-nitro- is the 7-nitrated derivative of 8-hydroxyquinoline, a bicyclic N,O-heteroaromatic system.

• Preferred name: 7-nitro-8-hydroxyquinoline (also rendered as 8-quinolinol, 7-nitro-)
• CAS: 18472-01-0 (per product data)
• CID: 205688 (per product data)
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula (literature): C9H6N2O3
• Molecular weight (literature): ~190.15 g/mol

Structural features (general description):

• Quinoline core (fused benzene–pyridine system) bearing a phenolic OH at C-8 and a nitro group at C-7 (on the benzenoid ring ortho to the hydroxyl).
• Bidentate chelation motif (N,O): ring nitrogen (quinoline N) and the 8-phenolic oxygen can concurrently bind metal ions, forming stable five-membered chelates.
• Electron-withdrawing nitro group decreases ring electron density, modulating acidity of the phenol and the ligand field properties of the chelate.
• 2D description: a planar bicyclic aromatic scaffold; the nitro substituent is adjacent to the hydroxyl on the benzenoid portion; the pyridine-type nitrogen is part of the second ring.

Notes:

• Any stereochemistry is not applicable (fully aromatic, achiral).

Synthetic Utility

Functional handles and typical transformations (literature, general):

• Phenolic OH at C-8:
  • O-alkylation with alkyl halides or sulfate esters (K2CO3/Cs2CO3, DMF/acetone) to give ethers with tunable donor properties and solubility.
  • O-acylation (acyl chlorides/anhydrides, base or DMAP catalysis) to furnish esters; hydrolytically removable.
  • Conversion to triflate provides an aryl electrophile for cross-coupling (Suzuki, Buchwald–Hartwig after appropriate transformation).
• Quinoline nitrogen:
  • Salt formation (e.g., with acids or metal ions) alters solubility and coordination behavior; quaternization (MeI, Meerwein salts) enables further elaboration.
• 7-Nitro group:
  • Reduction to 7-amino-8-hydroxyquinoline (Fe/NH4Cl, SnCl2/HCl, catalytic hydrogenation) opens access to ureas, amides, azo dyes (via diazotization), and cross-coupling after diazonium chemistry.
  • Participation in intramolecular charge transfer can be exploited in push–pull systems upon O-alkylation with donor groups.
• Chelation-assisted chemistry: the N,O set can transiently bind metals to direct ortho-functionalization or stabilize intermediates in oxidative couplings (reported for related 8-HQ systems).

Retrosynthetic value:

• Serves as a versatile intermediate toward libraries of quinolinyl ethers/amines with tunable electronics via manipulation at the 7-position and phenolic oxygen.

Target Specificity

This product is a small-molecule chemical and not a biological targeting reagent (e.g., antibody, aptamer, inhibitor standard). No target specificity data (antigen, epitope, clone, isotype, species reactivity) applies.

• Target specificity: Not applicable to this compound type.