Ethyl 2,2-dimethylpent-4-ynoate - ≥95% , CAS No.107540-02-3

CAS: 107540-02-3 Cat. No.: E1020655 Formula: C₉H₁₄O₂ Peso molecolare: 154.210 Numero EC: 890-976-1

GRADE & PURITY ≥95%

Storage

Room temperature

Specifications

Specifiche e purezza

≥95%

Condizioni di conservazione di stoccaggio

Room temperature

Purezza

≥95%

Nomi e identificatori

• Sorrisi canonici: CCOC(=O)C(C)(C)CC#C
• IUPAC Name: ethyl 2,2-dimethylpent-4-ynoate
• InChIKey: JVIMTZKDPIEVNB-UHFFFAOYSA-N
• INCHI: 1S/C9H14O2/c1-5-7-9(3,4)8(10)11-6-2/h1H,6-7H2,2-4H3
• Peso molecolare: 154.210

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Lipids and lipid-like molecules
    • Classe Fatty Acyls
      • Subclass Fatty acid esters

• Kingdom: Organic compounds
• Superclass: Lipids and lipid-like molecules
• Classe: Fatty Acyls
• Subclass: Fatty acid esters
• Intermediate Tree Nodes: Not available
• Direct Parent: Fatty acid esters
• Alternative Parents: Carboxylic acid esters Monocarboxylic acids and derivatives Acetylides Organic oxides Hydrocarbon derivatives Carbonyl compounds
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Fatty acid ester - Carboxylic acid ester - Acetylide - Monocarboxylic acid or derivatives - Carboxylic acid derivative - Organic oxygen compound - Organic oxide - Hydrocarbon derivative - Organooxygen compound - Carbonyl group - Aliphatic acyclic compound
• Descrizione: This compound belongs to the class of organic compounds known as fatty acid esters. These are carboxylic ester derivatives of a fatty acid.
• 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: 154.210 g/mol
• XLogP3: 1.900
• Hydrogen Bond Donor Count: 0
• Hydrogen Bond Acceptor Count: 2
• Rotatable Bond Count: 4
• Exact Mass: 154.099 Da
• Monoisotopic Mass: 154.099 Da
• Topological Polar Surface Area: 26.300 Ų
• Heavy Atom Count: 11
• Formal Charge: 0
• Complexity: 183.000
• 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 biological assay protocols (e.g., WB, IHC, IF, FC) are applicable to this small-molecule reagent. For synthetic uses, refer to the Reaction Conditions and Reaction & Applications sections for general laboratory protocols.

If employing CuAAC or other catalytic transformations, follow standard synthetic procedures, adapting catalyst loading, solvent ratios, and temperature to your scale and substrate solubility.

Biological Roles

This product is a small-molecule synthetic intermediate. It is not known as a natural metabolite, cofactor, or biomacromolecular ligand.

• No established biological role is associated with ethyl 2,2-dimethylpent-4-ynoate. Any interactions with biological systems would stem from generic physicochemical properties of small hydrophobic esters and terminal alkynes.
• In chemical biology contexts, the terminal alkyne can serve as a bioorthogonal handle for post-synthetic derivatization (e.g., CuAAC) after incorporation into a probe or scaffold. Such usage pertains to research workflows only and does not imply intrinsic biological function.

For all experiments involving cells or biomolecules, ensure that residual copper or organic solvents from synthetic steps are rigorously removed and that appropriate controls are included.

Buffer Applications

Not typically applicable. Ethyl 2,2-dimethylpent-4-ynoate is a hydrophobic organic building block, not a buffering agent. It does not define aqueous pH and has no conventional buffering range.

For aqueous bioconjugation workflows using the terminal alkyne (e.g., CuAAC), common buffers include phosphate-buffered saline (PBS) or HEPES with added sodium ascorbate and a Cu(I) source; select organic cosolvents (ethanol, t‑BuOH, or DMSO) to maintain substrate solubility as needed.

Green Alternatives

While the molecule itself is a specific synthetic building block, greener choices can be made around its use (solvent selection, catalysts, and workup), and sometimes by selecting functionally similar feedstocks when appropriate.

• Greener solvent options (literature guidance):

  • Replace THF/Et2O with 2‑MeTHF or CPME for metalation and coupling steps; both are derived from biorenewables (hemicellulose for 2‑MeTHF), have higher boiling points and lower peroxide tendencies (CPME), and enable easier solvent recovery.
  • Favor EtOAc or MeTHF/toluene over chlorinated solvents (DCM/DCE) for extractions and chromatography where feasible.
  • In CuAAC, aqueous ethanol or t‑BuOH/H2O blends reduce reliance on high‑boiling dipolar aprotics.

• Catalysis and reagent choices:

  • Employ copper wire or in situ Cu(I) from CuSO4/sodium ascorbate for click chemistry to avoid stoichiometric organometallics.
  • For Sonogashira couplings, use palladium at ppm levels with ligand-enabled systems, copper‑free variants, or heterogeneous catalysts to minimize metal waste.

• Workup/waste minimization:

  • Inline scavengers for residual metals (Si‑based scavengers) reduce aqueous waste from EDTA washes.
  • Implement solvent recycling and silica gel minimization (use reverse-phase or dry-load, or employ crystallization when possible).

• Comparison snapshot (general):

  • Conventional: THF/DCM, stoichiometric bases, copper co-catalyst → higher VOC and halogenated waste.
  • Greener: 2‑MeTHF/EtOAc, aqueous ethanol, copper‑free/low‑Pd systems → reduced hazard and improved sustainability.

Tradeoffs: Greener solvents may alter rates/solubility; re-optimize catalyst loading, base strength, and temperature to maintain yield/selectivity.

Pharmaceutical Uses

No pharmacopeial status or excipient role is provided for this item.

• Item-specific pharma/excipient info: Not specified for this item; refer to CoA/Spec Sheet.

Context (general for synthetic intermediates):

• Alkynyl esters are occasionally employed as intermediates in medicinal chemistry to build libraries via click chemistry, Sonogashira couplings, or hydrogenation sequences. The α,α-dimethyl motif can influence metabolic stability and conformational preferences of downstream compounds.
• If material is considered for any GMP-related synthesis step, ensure:
  • Lot-specific identity/purity confirmation (orthogonal analyses such as NMR, GC–MS, HRMS).
  • Control of residual solvents and elemental impurities according to ICH Q3C/Q3D in the final API/intermediate; this starting material itself is for research use only (per Product Data: For research use only).

No therapeutic or clinical claims are made or implied for this product.

Physical Properties

Item-specific specifications are not provided in the Product Data; consult the CoA/Spec Sheet for authoritative values.

• Appearance (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Storage Conditions (item-specific): Room temperature (per Product Data).

Qualitative/typical properties (literature/general for small alkynyl ethyl esters; not item specifications):

• Aggregate state: typically a low-viscosity, colorless to pale liquid at ambient conditions for C9 alkynyl ethyl esters.
• Volatility: moderate; esters of this size distill under atmospheric or reduced pressure. Avoid prolonged heating to limit ester hydrolysis.
• Odor: faint, ester-like (general observation for short-chain ethyl esters).
• Solubility: miscible with most common organic solvents (e.g., ethers, chlorinated solvents, aromatics, esters); low solubility in water due to hydrophobic backbone and limited H-bonding donors.
• Acid/base behavior: neutral compound; the terminal alkyne proton is relatively acidic for a hydrocarbon (pKa ~25, literature, for terminal alkynes in general), allowing formation of alkynyl metal species under strong basic conditions.
• Partitioning: expected to be hydrophobic (positive logP typical for C9 esters; literature trend), facilitating extraction into organic phases.
• Optical: refractive indices for related ethyl esters typically around 1.40–1.44 (literature trend; not item-specific).

Note: Do not treat the qualitative/literature statements above as specifications. For exact values relevant to your method validation or safety assessment, defer to the SDS and the lot-specific CoA.

Quality and Grades

• Grade/Purity (item-specific): Not specified for this item; refer to CoA/Spec Sheet for assay, impurity profile, and any stabilizers.

Interpretation and guidance (general):

• Research-use reagents such as alkynyl esters are typically supplied at high chemical purity suitable for synthesis and method development. When an explicit grade is given (e.g., “GC ≥98%,” “HPLC grade,” or “AR”), it reflects different analytical controls:
  • GC/HPLC purity: percentage area by chromatography for the neat material; higher grades reduce side-product background in catalysis and multistep synthesis.
  • Water/peroxide/metal limits: not specified for this item; if critical (e.g., for moisture-sensitive metalations), verify on the CoA or pre-dry/purify in-lab.
  • Stabilizers/inhibitors: not typically added to simple esters/alkynes; if present it will be listed explicitly on the label/CoA.
• Batch-to-batch documentation: Request CoA for your lot to confirm assay, residual solvents, and spectral ID (1H/13C NMR, IR, MS) as needed for GMP-adjacent workflows.
• Application notes:
  • Transition-metal-mediated couplings (CuAAC, Sonogashira) benefit from low sulfur/halide adventitious contaminants; if performance is sensitive, perform a short-path distillation or silica plug prior to use.
  • For quantitative kinetics or analytical standards, confirm purity by independent GC/GC–MS and adjust for assay when preparing stock solutions.

Reaction and Applications

Ethyl 2,2-dimethylpent-4-ynoate is a versatile terminal alkyne bearing an α,α-dimethyl-substituted ester. The combination of a deprotonatable alkyne and a sterically hindered carbonyl confers distinctive reactivity.

Key applications (general literature use cases):

• Alkynylation/metalation:
  • Formation of lithium/sodium/potassium acetylides with strong bases (e.g., n-BuLi, NaNH2). The resulting metal acetylides can add to electrophiles (carbonyls, epoxides) or engage in transmetallation for cross-couplings. Control temperature to suppress ester cleavage.
• Copper-catalyzed azide–alkyne cycloaddition (CuAAC):
  • The terminal alkyne undergoes regioselective 1,4-disubstituted 1,2,3-triazole formation with organic azides under Cu(I). The ester plus gem-dimethyl group can modulate lipophilicity and steric profile in triazole libraries.
• Sonogashira coupling:
  • Couples with aryl/vinyl halides or triflates under Pd/Cu catalysis to furnish internal alkynes adjacent to an α,α-dimethyl ester, a handle for further functionalization (hydrogenation, cycloaddition, hydrofunctionalization).
• Hydrofunctionalizations:
  • Hydroboration (e.g., catecholborane, 9-BBN) to vinyl boranes for subsequent Suzuki–Miyaura coupling.
  • Hydrosilylation or hydrostannylation as gateways to vinylsilanes/stannanes.
  • Radical and ionic additions (HX, halogens) with appropriate catalysts/conditions.
• Partial/complete hydrogenation:
  • Lindlar or P-2 nickel catalysts convert the alkyne to the Z-alkene; Pd/C or Raney Ni give alkanes. The α,α-dimethyl group biases sterics around the carbonyl, helpful in conformational control and avoiding enolization.

Practical notes:

• Dry, oxygen-free conditions improve outcomes for metalations/couplings.
• If ester stability is critical, avoid strong nucleophiles/bases at elevated temperature; consider milder bases (e.g., DIPEA) or fluoride-free, alcohol-free media to suppress transesterification.

Reaction Conditions

The following are representative literature-style conditions for terminal alkynes and alkynyl esters; they are general guidance, not item-specific specifications. Optimize for your substrate, scale, and equipment.

• CuAAC (azide–alkyne “click”):
  • Typical: CuSO4·5H2O (1–10 mol%) + sodium ascorbate (5–20 mol%) in t‑BuOH/H2O (1:1) or EtOH/H2O at rt to 50 °C, 1–16 h. Alternatively, premade Cu(I) sources (CuI, CuBr) with ligands (TBTA, THPTA) in mixed aqueous/organic media. Monitor by TLC/LC–MS.
• Sonogashira coupling (to aryl/vinyl halides):
  • Pd(PPh3)2Cl2 (1–3 mol%) + CuI (1–5 mol%), i‑Pr2NH or Et3N as base, THF, DMF, or toluene, rt to 80 °C, 1–24 h. Copper‑free variants: Pd with bulky phosphines (e.g., XPhos, P(t‑Bu)3) in amine/THF.
• Alkyne metalation (formation of acetylide):
  • n‑BuLi (1.1–1.5 equiv) in dry THF at −78 to −40 °C, then trap with electrophile (e.g., R–X via CuCN·2LiCl to form Gilman-type reagents, or with aldehydes/ketones at low T). Quench carefully; avoid conditions that hydrolyze the ester.
• Hydroboration–oxidation:
  • 9‑BBN or catecholborane (1.0–1.5 equiv), THF or toluene, 0 °C to rt, 1–4 h; then oxidative workup (H2O2/NaOH) to vinyl alcohol/ketone derivatives per alkyne regiochemistry.
• Partial hydrogenation:
  • Lindlar catalyst (5–10 wt%) under H2 (1 atm) in EtOAc, MeOH, or toluene at rt, 1–6 h, to give Z‑alkenes. Stop at desired conversion.
• Halogenation/hydrohalogenation:
  • NBS/NCS or HX under radical/ionic conditions in inert solvents (DCM, MeCN, toluene) with temperature control to manage selectivity and avoid ester cleavage.

General tips: maintain anhydrous, oxygen-free conditions for base- and metal-catalyzed steps; pre-dry glassware and solvents. If ester integrity is crucial, limit exposure to strong base/heat and avoid prolonged protic/basic media.

Safety and Handling

Authoritative safety information must be taken from the product SDS. The following are general precautions for alkynyl ethyl esters and terminal alkynes; they are not a substitute for the SDS.

• GHS classification, signal word, pictograms, and H-statements: Not specified for this item; refer to SDS.
• Likely hazards (general for small esters/alkynes): flammable liquid and vapor; may cause irritation to eyes/skin/respiratory tract on contact or inhalation; harmful if swallowed. Avoid ignition sources.
• Personal protective equipment (PPE): lab coat, safety glasses or splash goggles, and suitable chemical-resistant gloves (e.g., nitrile). Use in a fume hood to minimize vapor exposure.
• Handling notes:
  • Keep containers tightly closed. Ground/bond when transferring flammable liquids.
  • Prevent contact with strong bases if ester integrity must be preserved; terminal alkynes are deprotonated by strong bases (e.g., alkoxides/organolithiums).
  • Avoid strong oxidizers and strong acids/bases that can catalyze undesired reactions (oxidation, hydrolysis, polymerization is not typical, but alkynes can undergo addition reactions under harsh conditions).
• First aid (general):
  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Skin/eye contact: rinse with plenty of water for at least 15 minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical attention.
• Fire-fighting: use alcohol-resistant foam, dry chemical, or CO2. Water spray may be used to cool containers. Combustion can produce CO/CO2.
• Spill response: absorb with inert material (vermiculite, sand), ventilate area, eliminate ignition sources, and dispose per local regulations.

Always consult the official SDS for this product prior to use.

Solvent Selection

This product is a synthetic building block rather than a solvent. Selection of the reaction medium can strongly influence outcomes with alkynyl esters.

• Polarity/miscibility profile (general behavior): hydrophobic organic liquid, readily soluble in ethers (THF, MTBE, CPME), chlorinated solvents (DCM, DCE), aromatic solvents (toluene), esters (EtOAc), and polar aprotic solvents (DMF, DMSO). Insoluble to sparingly soluble in water.
• Choosing a solvent by transformation:
  • Base-mediated deprotonation/metalation of the terminal alkyne: use rigorously dry ethereal solvents (THF, 2-MeTHF, Et2O) at low temperature; hydrocarbon cosolvents (toluene, hexanes) can moderate reactivity.
  • CuAAC “click” reactions: t-BuOH/H2O, EtOH/H2O, or DMF/H2O mixtures commonly used; this substrate’s hydrophobicity may favor higher organic content or cosolvents like DMSO.
  • Sonogashira couplings: THF, toluene, dioxane, DMF, or MeCN are typical; choose base/solvent pairs that minimize ester saponification (e.g., i-Pr2NH in THF/toluene).
  • Hydroboration or hydrosilylation of alkynes: toluene or THF under inert atmosphere.
• Practical tips:
  • Avoid prolonged exposure to aqueous strong base in protic solvents to prevent ester hydrolysis.
  • For chromatography, normal-phase silica with nonpolar to medium-polar eluents (hexanes/EtOAc or hexanes/DCM) gives good resolution; minimize acid sites on silica to reduce transesterification.
• Comparison to alternatives: If protic media are required (bioconjugation-like settings), consider cosolvent systems to maintain solubility without compromising copper catalysis efficiency.

Storage and Reconstitution

• Storage (item-specific): Room temperature (per Product Data). Store in a tightly closed container in a dry, well-ventilated place away from ignition sources.
• Shipping: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers: Not specified for this item; refer to CoA/Spec Sheet.

Practical guidance (general):

• Protect from moisture and strong base to preserve the ester function. For long-term storage, keeping under inert gas (argon/nitrogen) and in amber glass can minimize oxidative or photochemical changes typical for unsaturated compounds.
• If low-temperature storage is preferred in your workflow, allow the sealed container to equilibrate to room temperature before opening to prevent moisture condensation.
• Reconstitution: Not applicable; supplied as a neat liquid reagent. For solution preparation, use dry, oxygen-free solvents when moisture-sensitive reactions (e.g., metalations, Pd-catalyzed couplings) are planned. Record exact concentration gravimetrically for stock solutions.
• Freeze–thaw: Not typically relevant. If stored as a solution, avoid repeated freeze–thaw by aliquoting into small, sealed vials.

Always consult the product label and SDS for authoritative handling and storage instructions.

Structure and Identity

Brief description: Ethyl 2,2-dimethylpent-4-ynoate is a branched alkynyl ester. It combines an ethyl ester functional group with a terminal alkyne on a five‑carbon chain, bearing two geminal methyl substituents at the α‑position to the carbonyl.

• Item-specific identifiers (from Product Data)

  • SKU: E1020655
  • Product Name: Ethyl 2,2-dimethylpent-4-ynoate
  • CAS: 107540-02-3
  • PubChem CID: 14459632
  • InChIKey: 171073 (as provided; note: non-standard length as given in Product Data)
  • 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 chemistry description)

  • Functional groups: an ethyl ester (–CO2Et) and a terminal alkyne (–C≡CH).
  • Substitution pattern: geminal dimethyl at C2 (α to the carbonyl), giving a quaternary center that increases steric hindrance and reduces α-enolization relative to non‑branched esters.
  • 2D structure in words: ethyl oxycarbonyl linked to a quaternary carbon bearing two methyl groups, followed by a two‑carbon spacer leading to a terminal alkyne. No rings; no heteroatoms beyond the ester oxygen atoms.
  • Stereochemistry: none (no stereogenic centers are present).

Synthetic Utility

Functional group set: terminal alkyne + sterically hindered ethyl ester (α,α-dimethyl). This combination is valuable in multistep synthesis because it couples a robust, transformable π‑unit with a carbonyl surrogate that is resistant to enolization.

• Strategic roles in synthesis (general):

  • Alkyne as a linchpin: enables installation of triazoles (CuAAC), vinyl motifs (hydroboration/hydrogenation), and halovinyls (HX addition), as well as cycloadditions (e.g., with nitrile oxides).
  • Chemoselectivity: the α,α-dimethyl ester is less prone to base-catalyzed side reactions at the α‑position, allowing selective deprotonation at the alkyne over enolization of the ester in many regimes.
  • Protecting-group behavior: the ethyl ester is stable to many nucleophiles/oxidants but can be cleaved under controlled basic or acidic hydrolysis when desired, releasing the corresponding carboxylate/acid.
  • Steric steering: gem-dimethyl substitution can bias addition to the alkyne in hydrofunctionalizations and influence conformational preferences in downstream fragments.

• Transformational repertoire:

  • Metalation/transmetallation to form C–C/C–X bonds (e.g., Sonogashira, Negishi after conversion to an organozinc via deprotonation–ZnCl2 quench).
  • Conversion of the ester: reduction (DIBAL-H to aldehyde at low T; LiAlH4/boranes to alcohol), transesterification, or amidation (via activation such as mixed anhydride or via acid after hydrolysis).
  • Sequential strategies: click-then-reduce, or hydrogenate-then-functionalize the resulting alkene/alkane while retaining the ester as a handle.

Overall, it serves as a compact, hydrophobic, and conformationally constrained fragment to diversify scaffolds efficiently.

Target Specificity

Not applicable. This product is a small-molecule chemical building block and is not an antibody, enzyme, nucleic acid, or targeted biological reagent. No antigen/epitope or species reactivity applies.