1,3-Dimethyl-5-pyrazolone - ≥96% , CAS No.2749-59-9

CAS: 2749-59-9 Cat. No.: D105385 Formula: C₅H₈N₂O Peso molecolare: 112.13 Numero EC: 220-389-2

GRADE & PURITY ≥96%

Synonyms

1,3-Dimethyl-5-pyrazolone | 3H-Pyrazol-3-one,4-dihydro-2,5-dimethyl- | BB 0257793 | W-107110 | DTXSID4074641 | EN300-52927 | NSC304 | NSC-304 | NSC 304 | SY030288 | F10825 | 2-Pyrazolin-5-one, 1,3-dimethyl- | 3H-Pyrazol-3-one, 2,4-dihydro-2,5-dimethyl- |

Storage

Store at 2-8°C

Shipped In

Wet ice

Specifications

Sinonimi

1,3-Dimethyl-5-pyrazolone | 3H-Pyrazol-3-one,4-dihydro-2,5-dimethyl- | BB 0257793 | W-107110 | DTXSID4074641 | EN300-52927 | NSC304 | NSC-304 | NSC 304 | SY030288 | F10825 | 2-Pyrazolin-5-one, 1,3-dimethyl- | 3H-Pyrazol-3-one, 2,4-dihydro-2,5-dimethyl- |

Specifiche e purezza

≥96%

Condizioni di conservazione di stoccaggio

Store at 2-8°C

Spedito in

Wet ice

Questo prodotto richiede spedizione a catena fredda. I servizi di terra e altri servizi economici non sono disponibili.

Purezza

≥96%

Nomi e identificatori

Pubchem Sid

504752843

Pubchem Sid Url

https://pubchem.ncbi.nlm.nih.gov/substance/504752843

Sorrisi canonici

CC1=NN(C(=O)C1)C

IUPAC Name

2,5-dimethyl-4H-pyrazol-3-one

InChIKey

NDELSWXIAJLWOU-UHFFFAOYSA-N

INCHI

1S/C5H8N2O/c1-4-3-5(8)7(2)6-4/h3H2,1-2H3

Isomeri SMILES

CC1=NN(C(=O)C1)C

Peso molecolare

112.13

Reaxy-Rn

606483

Reaxys-RN_link_address

https://www.reaxys.com/reaxys/secured/hopinto.do?context=S&query=IDE.XRN=606483&ln=

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organoheterocyclic compounds
    • Classe Azolines
      • Subclass Pyrazolines

• Kingdom: Organic compounds
• Superclass: Organoheterocyclic compounds
• Classe: Azolines
• Subclass: Pyrazolines
• Intermediate Tree Nodes: Not available
• Direct Parent: Pyrazolones
• Alternative Parents: N-alkylated hydrazones Carboxylic acids and derivatives Azacyclic compounds Organopnictogen compounds Organic oxides Hydrocarbon derivatives Carbonyl compounds
• Molecular Framework: Aliphatic heteromonocyclic compounds
• Substituents: Pyrazolinone - N-alkylated hydrazone - Azacycle - Carboxylic acid derivative - Organic nitrogen compound - Organic oxygen compound - Organopnictogen compound - Organic oxide - Hydrocarbon derivative - Organooxygen compound - Organonitrogen compound - Carbonyl group - Aliphatic heteromonocyclic compound
• Descrizione: This compound belongs to the class of organic compounds known as pyrazolones. These are compounds containing a pyrazole ring which bears a ketone.
• 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

• Solubilità: Soluble in water
• Punto di fusione (°C): 117°C
• Peso molecolare: 112.130 g/mol
• XLogP3: -0.300
• Hydrogen Bond Donor Count: 0
• Hydrogen Bond Acceptor Count: 2
• Rotatable Bond Count: 0
• Exact Mass: 112.064 Da
• Monoisotopic Mass: 112.064 Da
• Topological Polar Surface Area: 32.700 Ų
• Heavy Atom Count: 8
• Formal Charge: 0
• Complexity: 151.000
• 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 assay or kit-style application protocols are specified for this item.

• Tested applications (item-specific): Not specified for this item; refer to CoA/Spec Sheet if available.

• General laboratory usage examples (informational only)

  • Synthesis: Condensation with aromatic aldehydes (EtOH, catalytic piperidine, reflux) to form 4‑arylidene derivatives; isolate by filtration after cooling.
  • Azo dye formation: Prepare diazonium salt from an aniline at 0–5°C; add to a cold, stirred solution of 1,3‑dimethyl‑5‑pyrazolone in mildly alkaline aqueous ethanol; maintain pH ~8–9 and temperature <5°C for controlled coupling.

These are generic literature procedures; users should develop and validate their own protocols.

Biological Roles

This product is supplied strictly for research use; no clinical or diagnostic claims are made.

• General context (literature)

  • Pyrazolone scaffolds appear in numerous bioactive molecules (e.g., analgesic/antipyretic chemotypes like antipyrine derivatives). 1,3‑Disubstitution tunes hydrogen-bonding and lipophilicity but the specific biological roles of 1,3‑dimethyl‑5‑pyrazolone itself are not widely profiled.
  • As a chelating heterocycle, pyrazolones can bind transition metals; such complexes have been used as enzyme mimics or probes in biochemical studies (literature context, not specific to this item).

• Practical lab relevance

  • The compound can serve as a reference scaffold or precursor when assembling libraries of heterocycles for biochemical screening.

• Item-specific biological data

  • No item-specific biochemical potency, selectivity, or ADME data are provided for this product. Any biological testing should be performed by the end user under appropriate approvals.

Note: If biochemistry-driven properties (e.g., pKa, logD) are critical for your assay design, determine them experimentally under your assay conditions.

Buffer Applications

This compound is a neutral/weakly acidic heterocycle and is not a conventional buffering agent. It does not constitute a standard biological or chromatographic buffer system.

• If used in aqueous assays

  • Dissolve in compatible organic co-solvent (e.g., DMSO or ethanol) and dilute into a suitable buffer (e.g., phosphate, HEPES) while monitoring precipitation.
  • Adjust pH externally using established buffers; do not rely on this compound for pH control.

• For metal-complexation studies

  • Complex formation may be pH-dependent; standard buffer systems (acetate, phosphate, tris) should be employed, validated to avoid competing coordination.

Green Alternatives

• Solvent choices

  • Prefer greener polar protic solvents (ethanol, isopropanol) or bio-derived ethers (2‑MeTHF) instead of chlorinated solvents when performing condensations or crystallizations, provided solubility allows.
  • For polar aprotic needs, consider propylene carbonate or Cyrene (dihydrolevoglucosenone) as alternatives to DMF/DMSO where compatible.

• Catalysis and conditions

  • Employ organocatalysts or reusable solid bases (basic alumina, ion-exchange resins) to reduce soluble base waste in Knoevenagel condensations.
  • Microwave or flow conditions can shorten reaction times and reduce energy consumption.

• Workup/purification

  • Favor antisolvent crystallization (EtOH → water) to minimize silica usage and solvent-intensive chromatography.

• Comparative overview (general guidance)

  • Conventional vs greener options for common operations:
    • Base-promoted condensation: Piperidine in EtOH (conventional) → L-proline or ammonium acetate in bioethanol (greener), often at lower catalyst loadings.
    • Polar aprotic medium: DMF/DMSO (conventional) → propylene carbonate/Cyrene (greener), with attention to base strength and viscosity effects.
    • Chlorinated extraction: DCM/CHCl3 (conventional) → EtOAc/2‑MeTHF (greener) for phase separations.

• Tradeoffs

  • Greener solvents may alter tautomer equilibria and rates; small-scale screening is advised.
  • High-boiling green solvents can complicate solvent removal; plan for vacuum or switch to crystallization endpoints to avoid energy-intensive distillations.

Pharmaceutical Uses

• Regulatory/excipient status: Not specified for this item; no pharmacopeial monograph is indicated in the Product Data.

• Formulation context (general information)

  • While pyrazolone motifs occur in some legacy drug substances, 1,3‑dimethyl‑5‑pyrazolone itself is provided here solely as a research chemical/building block. It is not supplied as an API or excipient.

• Process chemistry relevance

  • Functions as an intermediate for synthesizing more complex pyrazolone-containing candidates, azo dye tracers, or metal-binding ligands used in assay development.

Any use in GMP or clinical manufacturing would require independent qualification, full impurity profiling, and supplier audit. This product is intended for non-GMP research only.

Physical Properties

Only general guidance is provided when exact item specifications are unavailable.

• Appearance (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Purity/grade (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Melting point (literature): Values for 1,3‑dimethyl‑5‑pyrazolone are reported in the literature but may vary with tautomeric composition and polymorph; consult primary literature or CoA for a definitive value for this lot.
• Boiling point (literature): Pyrazolones generally have high thermal stability and decompose or sublime rather than distill cleanly; specific BP for this compound is not widely used as a spec.
• Density (literature): Not broadly tabulated; expect typical values for small heteroaromatic lactams; exact value not specified for this item.
• Solubility (general behavior):
  • Polar organics (EtOH, MeOH, DMSO, DMF, acetonitrile): typically good to excellent solubility (literature trend for pyrazolones).
  • Water: low to moderate solubility depending on pH; increased solubility in basic aqueous media due to enolate formation (general behavior).
• pKa (literature, qualitative): The C-4 hydrogen is activated by the adjacent carbonyl and ring nitrogens; pyrazolone C–H acidity often lies in the 7–10 range, but precise values depend on substitution. Specific pKa for this exact compound is not specified for this item.
• LogP (literature): Expected low to moderate lipophilicity; exact value not specified for this item.
• Refractive index: Not applicable for solids; not specified for this item.

Note: Use the CoA/Spec Sheet for lot-specific QC data and physical constants if controlled as specifications.

Quality and Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

• Guidance on grades (general)

  • Synthetic/building-block grade: Suitable for organic synthesis, heterocycle elaboration, and ligand/dye precursor work where routine chromatographic purification is acceptable.
  • Higher-purity or low-UV grades (if offered): Favorable for analytical or spectroscopic applications where background absorbance and trace metals must be minimized. In the absence of an HPLC or spectrophotometric grade specification, assume normal organic synthesis grade and verify suitability for trace analysis experimentally.

• Stabilizers/additives

  • None indicated for this item. If stabilizers are present in a particular lot, they will be disclosed on the CoA/Spec Sheet.

• QC considerations for pyrazolones (general best practice)

  • Tautomeric mixtures can subtly influence NMR/IR; confirm identity by 1H/13C NMR and, if needed, variable-temperature NMR to assess tautomerism.
  • If using in Knoevenagel or azo-coupling reactions, monitor trace water and base content; Karl Fischer moisture and acid/base number may correlate with performance. Item-specific water content is not specified for this product.
  • Metals/UV cutoff: Not specified for this item; refer to CoA/Spec Sheet if such parameters are critical.

Reaction and Applications

• Key reactivity (general for 1,3-disubstituted pyrazolones)

  • Active methine at C-4: Under basic or amine-catalyzed conditions, forms an enolate/enamine that undergoes Knoevenagel-type condensations with aldehydes/ketones to furnish 4‑alkylidene or 4‑arylidene pyrazolones (valuable dye, ligand, and intermediate scaffolds).
  • Azo coupling partner: Acts as a coupling component with diazonium salts to give intensely colored azo dyes; methyl substitution modulates coupling position and bathochromic shifts.
  • Michael additions/annulations: The enolate can add to activated alkenes or participate in multicomponent reactions (e.g., Hantzsch-like or Biginelli variants) forming polyfunctional heterocycles.
  • Coordination chemistry: Carbonyl and ring nitrogens chelate metals, enabling formation of analytical complexes and catalytic ligands (literature reports for pyrazolone-derived ligands).

• Representative transformations (literature examples; conditions vary)

  • Condensation with benzaldehydes in EtOH, catalytic piperidine, reflux → 4-arylidene products.
  • Alkylation at C-4 with alkyl halides using K2CO3/Cs2CO3 in DMF, 20–80°C → 4‑alkyl derivatives (site-selectivity influenced by base and temperature).
  • Azo coupling with anilinium diazonium salts in cold, slightly alkaline media → mono- or bis-azo dyes.

• Practical notes

  • Control water content and base strength to steer N- vs C-alkylation; N1-methyl reduces competing N-alkylation at that site.
  • Monitor reactions by UV–vis (for azo coupling) and by TLC/HPLC. Pyrazolone chromophores have useful UV absorbance for tracking.
  • Purification often by crystallization from alcohols or by flash chromatography (EtOAc/hexane or MeOH/DCM systems).

Reaction Conditions

The following are general, literature-derived guidelines for pyrazolone chemistry. Optimize for your substrate set.

• Knoevenagel-type condensation at C-4

  • Solvent: EtOH, i‑PrOH, or MeCN.
  • Catalyst/base: Piperidine (5–20 mol%), pyridine, ammonium acetate, or L‑proline.
  • Temperature/time: RT to reflux; 0.5–6 h typically.
  • Notes: Remove water (Dean–Stark in toluene/PhMe if solubility allows, or molecular sieves in MeCN) to drive equilibrium.

• C‑Alkylation

  • Solvent: DMF or DMSO (dry).
  • Base: K2CO3, Cs2CO3, NaH (for more challenging electrophiles; handle cautiously).
  • Electrophiles: Benzyl/allyl halides, MeI/EtI (consider N‑ vs C‑selectivity; N1‑methyl reduces N‑alkylation routes).
  • Temperature: 20–80°C; 1–12 h.

• Azo coupling

  • Conditions: Generate aryl diazonium salt at 0–5°C; couple into 1,3‑dimethyl‑5‑pyrazolone in mildly alkaline medium (Na2CO3/NaOAc) or pyridine-containing solvent.
  • Monitoring: UV–vis for chromophore development; maintain low temperature to control regioselectivity.

• Metal complexation

  • Solvent: Alcohols or MeOH/MeCN mixtures; adjust pH (6–9) to favor chelation.
  • Metals: Cu(II), Fe(III), Ni(II) salts commonly yield colored complexes (literature context).

• Typical workups

  • Quench bases with aqueous NH4Cl; extract with EtOAc.
  • Crystallize arylidene/azo products from EtOH or EtOH/water.

Expected yields (literature generalities): 60–90% for well-matched condensations; 40–80% for C‑alkylations depending on electrophile; azo couplings often 60–85% with controlled temperature.

Safety and Handling

• Regulatory/SDS notes

  • GHS classification (item-specific): Not specified for this item; refer to the SDS.
  • Signal word, hazard (H) statements, and pictograms: Not specified for this item; refer to the SDS.
  • Research use: For research use only. Not for human or veterinary use.

• Anticipated hazards (general for pyrazolones; consult SDS for definitive guidance)

  • May cause irritation to skin, eyes, and respiratory tract if dust or solutions are handled without protection.
  • Avoid inhalation of dust and contact with skin/eyes. Wash thoroughly after handling.

• PPE and engineering controls

  • Wear lab coat, safety glasses/goggles, and appropriate chemical-resistant gloves (e.g., nitrile).
  • Handle powders/solutions in a fume hood to minimize inhalation exposure.

• Storage and incompatibilities

  • Storage (item-specific): Store at 2–8°C. Keep container tightly closed, desiccated if possible.
  • Shipping (item-specific): Shipped on wet ice.
  • Incompatibilities (general): Strong oxidizers; strong bases/acids can induce decomposition or tautomerization/condensation. Avoid prolonged exposure to moisture and light if purity is critical for condensation chemistry.

• First-aid overview (general)

  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Skin: Wash with soap and water; remove contaminated clothing.
  • Eyes: Rinse cautiously with water for several minutes; remove contact lenses if present.
  • Ingestion: Rinse mouth; seek medical advice.

Always defer to the product SDS for authoritative hazard classification and emergency procedures.

Solvent Selection

1,3-Dimethyl-5-pyrazolone behaves as a moderately polar heterocycle with a hydrogen-bond acceptor carbonyl and ring nitrogens. Solvent choice depends on the transformation (condensation, alkylation, azo coupling) and desired tautomer distribution.

• Miscibility/solubility trends (general/literature)

  • Good solubility: DMSO, DMF, NMP, methanol, ethanol, acetonitrile.
  • Moderate solubility: Acetone, ethyl acetate.
  • Limited solubility: Nonpolar hydrocarbons (hexanes, toluene) unless warmed or with co-solvent.
  • Aqueous media: Solubility increases with basic pH (enolate formation); limited under neutral conditions.

• Selection by application

  • Knoevenagel/aldol-type condensations at C-4: Protic alcohols (EtOH, i-PrOH) or acetonitrile with catalytic piperidine/pyridine or ammonium acetate are common.
  • Azo coupling (as coupling component): Slightly alkaline aqueous ethanol or pyridine/acetic conditions can promote coupling with diazonium salts.
  • N- or C-alkylations: Polar aprotic solvents (DMF, DMSO) with appropriate base (e.g., K2CO3, Cs2CO3) to favor the desired site selectivity.

• Comparison to alternatives (general)

  • Relative to less substituted pyrazolones, the N1-methyl reduces N-alkylation ambiguity and can simplify product profiles.
  • Compared with 1-phenyl-3-methyl-5-pyrazolone (PMP), this compound is less hydrophobic and often more soluble in polar solvents, aiding homogeneous reactions.

• Practical tips

  • Dry polar aprotic solvents improve yields in base-promoted condensations.
  • For aqueous or biphasic conditions, use phase-transfer catalysts if C-4 deprotonation is rate-limiting.

Storage and Reconstitution

• Storage (item-specific)

  • Store at 2–8°C in the original, tightly closed container.
  • Protect from moisture and prolonged light exposure. Consider storing under inert atmosphere for long-term stability if repeatedly opened.

• Shipping (item-specific)

  • Shipped on wet ice.

• Stability notes (general)

  • Pyrazolones are typically stable solids; however, extended exposure to strong base or acids can promote degradation or self-condensation.
  • Avoid repeated freeze–thaw of solutions; prepare fresh solutions as needed.

• Solution preparation

  • Solvents: DMSO, DMF, ethanol, or acetonitrile typically dissolve the compound readily (literature trend). For aqueous work, use an organic co-solvent and/or mild base to aid solubility.
  • Concentrations: Prepare stock solutions at 10–100 mM depending on solubility and intended use; filter (0.2 µm PTFE) if particulate forms.
  • Storage of solutions: Short term at 2–8°C (days) or at −20°C (weeks) in amber vials; verify stability by LC/MS or HPLC before use. Item-specific solution stability is not specified for this product.

• Reconstitution (if supplied as a solid)

  • Warm to room temperature in a desiccator before opening to prevent moisture uptake.
  • Add measured volume of dry solvent, swirl to dissolve, and use promptly.

Always consult the CoA/Spec Sheet for any lot-specific guidance.

Structure and Identity

Brief description: 1,3-Dimethyl-5-pyrazolone is a five‑membered heteroaromatic lactam (pyrazolin-5-one) bearing methyl substituents at N1 and C3. The core features a 1,2-diazole ring with a carbonyl at C-5 and tautomerizable keto–enol character.

• Item-specific identifiers (from Product Data)

  • CAS: 2749-59-9
  • SKU: D105385
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general/literature description)

  • Ring system: Pyrazolin-5-one (a pyrazole-related 5-membered ring containing two adjacent ring nitrogens at positions 1 and 2 and a carbonyl at C-5).
  • Substitution pattern: N1‑methyl and C3‑methyl; position 4 is activated (vinylogous/active methine) and commonly engaged in condensation reactions.
  • Functional groups: Cyclic amide (lactam) carbonyl; adjacent ring nitrogens (one imide-like N, one imine-like N) enabling tautomerism and H‑bonding/coordination.
  • Tautomerism: Keto–enol equilibrium at C-5, and possible prototropy involving N2; the keto form predominates in most polar media (literature).

• 2D structure (verbal)

  • A five-membered ring with adjacent N–N (positions 1 and 2). The C-5 bears a carbonyl (C=O). The N at position 1 bears a methyl group. The C at position 3 (alpha to N2) bears a methyl group. Position 4 is a methine (or part of an enolizable double bond in the enol form).

Synthetic Utility

• Functional group leverage

  • The 5‑one carbonyl and adjacent N–N ring create an ambident anion on deprotonation at C‑4, enabling C–C bond formation via condensations and alkylations.
  • N1‑methyl substitution locks one nitrogen, simplifying regioselectivity during further N‑functionalization (if any) and focusing reactivity at C‑4.

• Retrosynthetic value

  • 1,3‑Dimethyl‑5‑pyrazolone serves as a masked 1,3‑dicarbonyl equivalent in many transformations; its enolate can mimic β‑dicarbonyl behavior in Knoevenagel and Michael chemistry.
  • Useful as a coupling component to rapidly install azo chromophores; downstream diversification at the arylidene or azo substituents expands chemical space.

• Named/typical reactions (literature)

  • Knoevenagel condensations with aldehydes/ketones (amine/base catalysis).
  • Azo coupling with diazonium salts (cold, mildly basic conditions).
  • Michael additions to activated olefins; annulations forming bicyclic heterocycles under multicomponent conditions.

• Downstream elaboration

  • Hydrogenation/isomerization of arylidene products; cross-coupling if a halogen is present on the arylidene partner.
  • Metal complexation to generate catalytic or sensing complexes (Cu, Fe, Ni, etc.).

• Practical guidance

  • Choose bases that favor C‑ over N‑functionalization (e.g., K2CO3/Cs2CO3, DBU) and control temperature to avoid over-alkylation.
  • Tautomeric form can influence NMR; confirm structures with HMBC/HSQC and, if needed, X‑ray crystallography for key derivatives.

Target Specificity

Not applicable. This product is a small-molecule heterocycle and is not an antibody, protein, or targeted biological reagent.

• Antigen/epitope: Not applicable.
• Species reactivity: Not applicable.
• Clone/isotype: Not applicable.

No target-binding specificity data are provided or implied for this item.