4,8-Dimethyl-2-hydroxyquinoline - ≥95% , CAS No.5349-78-0

CAS: 5349-78-0 Cat. No.: D1073009 分子式: C₁₁H₁₁NO 分子量: 173.21 EC番号: 654-398-1 PubChem CID: 220708

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

仕様と純度

≥95%

保管条件

Room temperature

純度

≥95%

名前と識別子

• カノニカル・スマイル: CC1=C2C(=CC=C1)C(=CC(=O)N2)C
• IUPAC Name: 4,8-dimethyl-1H-quinolin-2-one
• InChIKey: NJUAEGGYLOZMGV-UHFFFAOYSA-N
• INCHI: 1S/C11H11NO/c1-7-4-3-5-9-8(2)6-10(13)12-11(7)9/h3-6H,1-2H3,(H,12,13)
• 異性体SMILES: CC1=C2C(=CC=C1)C(=CC(=O)N2)C
• PubChem CID: 220708
• 分子量: 173.21

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organoheterocyclic compounds
    • 分類 Quinolines and derivatives
      • Subclass Quinolones and derivatives

• Kingdom: Organic compounds
• Superclass: Organoheterocyclic compounds
• 分類: Quinolines and derivatives
• Subclass: Quinolones and derivatives
• Intermediate Tree Nodes: Not available
• Direct Parent: Hydroquinolones
• Alternative Parents: Hydroquinolines Pyridinones Methylpyridines Benzenoids Heteroaromatic compounds Lactams Azacyclic compounds Organopnictogen compounds Organooxygen compounds Organonitrogen compounds Organic oxides Hydrocarbon derivatives
• Molecular Framework: Aromatic heteropolycyclic compounds
• Substituents: Dihydroquinolone - Dihydroquinoline - Pyridinone - Methylpyridine - Pyridine - Benzenoid - Heteroaromatic compound - Lactam - Azacycle - Organic nitrogen compound - Organopnictogen compound - Organooxygen compound - Organonitrogen compound - Organic oxygen compound - Hydrocarbon derivative - Organic oxide - Aromatic heteropolycyclic compound
• 説明: This compound belongs to the class of organic compounds known as hydroquinolones. These are compounds containing a hydrogenated quinoline bearing a ketone group.
• 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

化学的性質と物理的性質

• 分子量: 173.210 g/mol
• XLogP3: 1.600
• Hydrogen Bond Donor Count: 1
• Hydrogen Bond Acceptor Count: 1
• Rotatable Bond Count: 0
• Exact Mass: 173.084 Da
• Monoisotopic Mass: 173.084 Da
• Topological Polar Surface Area: 29.100 Ų
• Heavy Atom Count: 13
• Formal Charge: 0
• Complexity: 257.000
• 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

Not applicable as standardized bioassay protocols.

• No vendor-validated applications (e.g., WB, IHC, IF, FC) are specified for this small molecule. For custom uses (e.g., metal-sensor preparation or ligand synthesis), follow literature procedures under Reaction Conditions and Synthetic Utility and validate in your system.
• Research Use Note: For research use only.

Biological Roles

General information (no clinical claims; literature-based)

• Structural motif: Quinolinol scaffolds appear in natural products and synthetic bioactive ligands. The 2-hydroxyquinoline/2-quinolinone tautomeric pair engages in hydrogen bonding and metal coordination, influencing binding to biomacromolecules.
• Metal binding: The N,O-bidentate site can chelate biologically relevant metals (e.g., Fe, Cu, Zn). Substituents at C4/C8 modulate lipophilicity and potentially membrane permeability and target affinity in probe design.
• Fluorescent probes: Quinolinol metal complexes often exhibit distinctive emission, enabling use in sensing and imaging probes (e.g., Zn2+ reporters). Methyl substitution can improve photostability by reducing nonradiative decay pathways (literature trend for quinoline fluorophores).
• Enzyme/protein interactions: The quinolinone tautomer can act as a hydrogen-bond acceptor/donor, a feature leveraged in medicinal chemistry SAR; however, specific biological targets for 4,8-dimethyl-2-hydroxyquinoline are not established here.

Notes for research use

• For in vitro work, prepare fresh stock solutions in DMSO or ethanol, and evaluate aggregation/solubility at working concentrations.
• Assess metal contamination of buffers to avoid unintended chelation effects in biochemical assays.

Item-specific biological data

• None specified for this item; refer to literature and design experiments accordingly. For research use only.

Buffer Applications

Not typically applicable.

• 4,8-Dimethyl-2-hydroxyquinoline is not a conventional buffering agent and lacks a well-defined, narrow pKa window suitable for standard biological buffers. While its phenolic OH and ring nitrogen display acid–base behavior, the compound is used as a research reagent/ligand rather than as a buffer component.
• For experiments in aqueous media, select established buffers (e.g., phosphate, HEPES, MOPS, Tris) in the appropriate pH range and evaluate compound solubility by co-solvent addition (ethanol or DMSO ≤1–2% v/v where compatible).

Green Alternatives

Context

• 4,8-Dimethyl-2-hydroxyquinoline is a specialty heteroaromatic building block/ligand rather than a bulk solvent. Greener considerations focus on solvents, oxidants, and energy inputs used with this compound.

Greener choices (literature/general guidance)

• Solvents: Prefer ethanol, isopropanol, 2-MeTHF, CPME, or water/EtOH mixtures over chlorinated solvents when compatible with solubility and selectivity requirements.
• Oxidants for N-oxide formation: Aqueous H2O2 (with AcOH or catalyst) can replace mCPBA in some protocols, reducing halogenated waste.
• Bases: Use carbonate bases (K2CO3, Cs2CO3) or organic bases (DBU, DIPEA) instead of strong inorganic hydroxides when feasible.
• Energy: Microwave or flow conditions can reduce reaction times and improve energy efficiency for O-alkylations or cyclizations.

Illustrative comparison (general; not item-specific)

• Chlorinated solvents (DCM/CHCl3): Excellent solubility, easy workup; environmental/health concerns, disposal burden.
• Ethanol/2-MeTHF: Renewable sources, lower toxicity; may require longer times or altered temperatures to match performance.

Trade-offs and best practices

• Solubility constraints may necessitate polar aprotic solvents (DMF/DMSO); mitigate by solvent recovery and minimizing volumes.
• Implement in-process controls to avoid over-oxidation or over-alkylation, reducing waste.
• Consider catalytic variants (e.g., catalytic bases, phase-transfer catalysts) to lower reagent loadings.

Pharmaceutical Uses

No therapeutic claims; research and formulation context only.

• Status: No pharmacopeial monograph known for 4,8-dimethyl-2-hydroxyquinoline (literature check recommended). It is primarily a research intermediate/ligand.
• Potential roles (general):
  • Synthetic intermediate en route to quinolinone derivatives or metal–ligand complexes used in discovery programs.
  • Fluorescent/chemosensor precursor after appropriate derivatization or metal complexation.
• Excipient use: Not typical; phenolic, aromatic heterocycles are generally not used as excipients without extensive safety/tox data.

Process considerations (general)

• For preclinical discovery support, control residual metals and solvent levels in isolated intermediates per ICH Q3D/Q3C where relevant.
• Photostability and tautomerism should be assessed if incorporated into assay reagents or diagnostic components.

Item-specific pharmaceutical information

• Not specified for this item; refer to CoA/Spec Sheet. For research use only.

Physical Properties

Item-specific specifications

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.

Literature/computed properties (for guidance; not item specifications)

• Molecular formula: C11H11NO (literature inference for 4,8-dimethyl-2-hydroxyquinoline)
• Molecular weight: ~173.21 g/mol (computed from formula)
• Tautomerism: Exists as 2-hydroxyquinoline/2-quinolinone tautomers; tautomer ratio is solvent- and pH-dependent (literature).
• Acid-base behavior: Phenolic OH pKa typically ~10–11 for quinolinols; conjugate acid of quinoline N pKaH typically ~4–5 (literature ranges; substitution will shift values modestly).
• LogP: Aromatic heterocycles of this size with two methyls and one OH commonly show logP in the ~2.5–3.2 range (estimated; QSAR/literature analogs).
• Solubility (qualitative): Expected to be sparingly soluble in water; soluble in common organic solvents (e.g., DCM, chloroform, toluene, THF, acetone, ethanol, methanol, DMF, DMSO). Actual solubility should be verified experimentally.
• UV-vis: Quinolinol chromophores typically absorb in the near-UV (ca. 250–360 nm), with solvent- and tautomer-dependent bands (literature). No item-specific UV cutoff provided.
• Melting/boiling point, density, refractive index: Not specified for this item; refer to CoA/Spec Sheet.

Notes

• Use these literature values for initial planning only; for QC-sensitive work, verify with batch-specific CoA.

Quality and Grades

Item-specific quality information

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/additives: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for this compound class

• Quinolinol derivatives are often used as research intermediates, ligands, and analytical reagents. For spectroscopic or coordination-chemistry applications, low levels of UV-active and metal contaminants are typically desirable; verify with the batch CoA when these parameters are critical.
• If HPLC/UV work is planned, consider assessing baseline absorbance and any fluorescent impurities; HPLC-grade solvents and glassware passivation can reduce background signals.
• Trace metals: For metal-complexation studies, background metal content of the solid can influence apparent binding stoichiometry. If not specified, pre-treat with acid-washed glassware and use chelexed solvents to minimize adventitious metals.
• Water/peroxide/UV cutoff: Not specified for this item; refer to CoA/Spec Sheet.

Documentation

• For regulated workflows or documentation-heavy projects, request the lot-specific CoA that includes assay method, impurity profile (if available), and recommended test methods (e.g., NMR, HPLC, MS).

Reaction and Applications

Representative applications (literature/general; expand/adjust per project needs)

• Ligand/chelator chemistry: 2-hydroxyquinoline motifs can bind metals through the N,O-bidentate set (after deprotonation), forming stable five-membered chelates with transition metals (e.g., Al(III), Zn(II), Cu(II), Ir(III)). The 4,8-dimethyl pattern modulates sterics/electronics and can tune emission of organometallic luminophores.
• O-Functionalization: The phenolic OH undergoes O-alkylation and O-acylation to give ethers/esters; useful for protecting-group strategies or tuning solubility and donor strength.
• N-oxidation/N-oxide chemistry: Quinoline N-oxides can be accessed (e.g., mCPBA), enabling subsequent rearrangements (Meyen–Fischer, Boekelheide) or directed functionalization.
• Electrophilic aromatic substitution (EAS): Remaining ring positions (e.g., those not blocked by methyls at C4/C8) can undergo nitration, sulfonylation, or halogenation under controlled conditions; directing effects arise from both N and O.
• Cross-coupling platforms: Halogenated derivatives (e.g., bromo at C5–C7) of this scaffold can be prepared and used in Suzuki–Miyaura, Buchwald–Hartwig, or Sonogashira couplings to access functionalized libraries.
• Materials/sensing: Quinolinol metal complexes show notable photophysical properties; methyl substituents can suppress nonradiative decay.

Practical tips

• Control tautomerism via solvent and pH to influence reactivity (O- vs N-functionalization).
• Dry conditions and base choice (K2CO3, Cs2CO3) are key for selective O-alkylations; phase-transfer catalysis can enhance rates.
• For chelation, mild base (e.g., Et3N) facilitates deprotonation without over-alkalinity that may cause side reactions.

Reaction Conditions

General literature conditions (guidance; optimize per system)

• O-alkylation (ether formation):

  • Reagents: Alkyl halide (e.g., MeI, BnBr), base (K2CO3 or Cs2CO3)
  • Solvent: Acetone, acetonitrile, or DMF
  • Temperature/time: RT to 60 °C, 2–24 h
  • Notes: Dry conditions; consider phase-transfer catalysts (TBAB) for less reactive halides.

• O-acylation (ester formation):

  • Reagents: Acyl chloride or anhydride; base (pyridine, Et3N)
  • Solvent: DCM or toluene; alternatively neat with Ac2O
  • Temperature: 0 °C to RT

• N-oxidation (quinoline N-oxide):

  • Reagents: mCPBA in DCM or CHCl3; or H2O2/AcOH
  • Temperature: 0–25 °C; typical times 1–6 h
  • Notes: Monitor to avoid over-oxidation.

• Halogenation (for cross-coupling precursors):

  • Reagents: NBS/NCS or electrophilic halogen sources
  • Solvent: DMF/AcOH or MeCN
  • Temperature: 0–25 °C; regioselectivity influenced by methyl groups and directing effects.

• Metal complexation (N,O-chelates):

  • Metal salts: Zn(II), Al(III), Cu(II), Ir(III) precursors
  • Solvent: EtOH/MeOH or mixed EtOH/water; mild base (Et3N) to deprotonate
  • Conditions: RT to reflux; 1–12 h; isolate by precipitation/crystallization.

Expected outcomes

• Yields and selectivity are substrate- and condition-dependent; consult the literature for closely related quinolinol systems and confirm by NMR/MS/HRMS.

Safety and Handling

Item-specific hazard data

• GHS classification, pictograms, signal word, and H-statements: Not specified for this item; refer to SDS.

General safety considerations (literature/general guidance)

• Likely hazards: Aromatic nitrogen heterocycles and phenolic compounds can cause skin/eye irritation and may be harmful if swallowed or inhaled. Avoid dust generation.
• PPE: Use appropriate lab coat, safety glasses or goggles, and nitrile gloves. Handle in a chemical fume hood to avoid inhalation of dust or vapors from hot solutions.
• Storage incompatibilities: Keep away from strong oxidizing agents and strong bases/acids that may induce decomposition, O/N-oxidation, or salt formation. Avoid prolonged exposure to light and air if purity is critical.
• Tautomer/phenol behavior: Phenolic OH can form salts with strong bases; neutralize spills with inert absorbents and collect for disposal according to local regulations.
• Thermal considerations: Avoid overheating; aromatic heterocycles may decompose on strong heating.
• First aid overview: If on skin/eyes, rinse with plenty of water for at least 15 minutes; remove contaminated clothing. If inhaled, move to fresh air. If ingested, rinse mouth; do not induce vomiting; seek medical attention. Always follow the SDS for definitive instructions.

Disposal

• Dispose of as organic laboratory waste; incineration with energy recovery is common where permitted. Follow institutional and regulatory requirements.

Solvent Selection

Compound type and polarity

• Heteroaromatic phenol (quinolinol) with moderate hydrophobicity and one H-bond donor/acceptor pair (O/N). Expected to be sparingly soluble in water and readily soluble in many organic solvents.

Miscibility/solubility profile (literature guidance)

• Polar aprotic: DMSO, DMF, NMP – excellent solubility; good for stock solutions and SNAr/O-alkylations.
• Protic: Methanol, ethanol, isopropanol – typically good solubility; useful for recrystallization and metal complexation studies.
• Moderately polar aprotic: Acetone, acetonitrile, THF – often good solubility; suitable for alkylations/acylations with appropriate bases.
• Nonpolar/aromatic: Toluene, chlorinated solvents (DCM, CHCl3) – usually good solubility; favorable for electrophilic aromatic substitutions or high-temperature reactions (toluene/xylene).

Selection tips

• Spectroscopy/photophysics: Dry, UV-transparent solvents (ethanol, acetonitrile) minimize background and support tautomer-dependent spectra.
• O-alkylation/acylation: Choose polar aprotic media (DMF, acetone, MeCN) with mild inorganic bases (K2CO3, Cs2CO3). Avoid strongly basic, highly nucleophilic solvents if chemoselectivity is a concern.
• Metal complexation: Alcohols or mixed alcohol/water systems can aid crystallization of chelates; buffer pH to control deprotonation of the phenol.

Comparison (general)

• DMSO vs DMF: DMSO offers higher solubility and benign evaporation profile but can participate in oxidations; DMF offers lower viscosity and easier removal.
• Ethanol vs methanol: Ethanol is less toxic and greener; methanol offers higher polarity and faster crystallization in some systems.

Storage and Reconstitution

Item-specific storage

• Storage Conditions: Room temperature (per Product Data). Protect from moisture and light in a tightly closed container for optimal stability.
• Shipped In: Not specified for this item; refer to CoA/Spec Sheet.

General guidance

• Solid handling: Store in amber glass with desiccant if possible to minimize moisture uptake and photodegradation. Avoid prolonged exposure to air if metal-trace sensitivity is critical for your application.
• Reconstitution/stock solutions: Prepare concentrated stocks in dry DMSO, DMF, ethanol, or methanol. Typical starting concentrations: 10–100 mM depending on solubility; filter if particulates persist.
• Aqueous use: Limited intrinsic water solubility is expected. Use co-solvents (≤1–2% DMSO/EtOH) or form transient basic solutions to dissolve, then adjust pH as needed (mind deprotonation of the phenol and potential complexation to adventitious metals).
• Freeze–thaw: For organic solutions, aliquot to avoid repeated freeze–thaw cycles; store at −20 °C for DMSO/DMF stocks when long-term storage is required. Inspect for precipitation or discoloration before use.

Specifications

• Appearance, purity, water content, metal limits: Not specified for this item; refer to CoA/Spec Sheet.

Structure and Identity

Brief description: 4,8-Dimethyl-2-hydroxyquinoline is a methyl-substituted quinolinol bearing a phenolic OH at C2 and methyl groups at C4 and C8; it exists in tautomeric equilibrium with the corresponding 2-quinolinone.

• Item-specific identifiers (from Product Data)

  • Product name: 4,8-Dimethyl-2-hydroxyquinoline
  • CAS: 5349-78-0
  • CID: 220708
  • InChIKey: 240374 (as provided)
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.

• Computed/literature structural details (general information)

  • Likely molecular formula (literature inference for this substitution pattern): C11H11NO
  • Calculated molecular weight: ~173.21 g/mol (literature/computed)
  • Core scaffold: quinoline (benzannulated pyridine)
  • Functional groups: phenolic OH at C2 (tautomerizable to 2-quinolinone), ring nitrogen (weakly basic), two ring methyl groups at C4 and C8 (steric/electronic modulation)
  • Tautomerism: 2-hydroxyquinoline ⇄ 2-quinolinone; intramolecular H-bonding (O–H···N or N–H···O) may stabilize specific tautomers depending on solvent/pH.
  • 2D description: a bicyclic system (fused benzene–pyridine). OH is ortho to the ring nitrogen (on the pyridine ring), with methyl substituents placed para to N (C4) and on the benzene ring (C8). No stereocenters; fully aromatic.

• Notes

  • Where exact identifiers (e.g., SMILES, validated InChIKey) are required for regulatory or database use, consult the product CoA/SDS or authoritative databases for confirmation.

Synthetic Utility

Reactivity map (general for quinolinols; tailored by 4,8-dimethyl substitution)

• O-site: Phenolic OH enables O-alkylation (BnBr, MeI) and O-acylation (Ac2O, acyl chlorides) to access ethers/esters, tuning solubility/electronics.
• N-site: The ring nitrogen can be oxidized to N-oxides (mCPBA, H2O2/AcOH), unlocking rearrangements (Boekelheide) or directed ortho-functionalization.
• C–H functionalization: Positions not blocked by Me at C4/C8 (e.g., C3, C5–C7) are candidates for electrophilic substitution or metal-catalyzed C–H activation; directing by N/O or their protecting groups can be exploited.
• Halogenation as a handle: Installing Br/Cl at reactive positions enables cross-couplings (Suzuki, Buchwald–Hartwig, Sonogashira) to diversify the scaffold.
• Chelation-driven assembly: Deprotonated 2-hydroxy function with ring N forms N,O-bidentate ligands giving five-membered metallacycles; valuable for catalysis or photofunctional materials.

Strategic notes

• Tautomer control (2-hydroxy vs 2-quinolinone) can steer O- vs N-functionalization; polar aprotic solvents and mild bases favor O-alkylation.
• The 4,8-dimethyl groups increase steric bulk and electron donation, often reducing overreaction and guiding regioselectivity.
• Protection options: Silyl or benzyl protection of the phenol can mask O-coordination during metalation or cross-coupling sequences.

Target Specificity

Not applicable.

• This product is a small-molecule research chemical, not an antibody or biologic. No antigen/epitope specificity, clone, isotype, or species reactivity applies.