m-Xylene-(dimethyl-¹³C₂) - ≥99 atom% 13C , CAS No.117713-57-2

CAS: 117713-57-2 Cat. No.: M473815 Formula: C₆H₄(¹³CH₃)₂ Peso molecolare: 108.15 Numero EC: 687-083-2

GRADE & PURITY ≥96%(SDS-PAGE)

Synonyms

m-Xylene-dimethyl-13C2 | m-Xylene-(dimethyl-13C2), 99 atom % 13C | m-Xylene-alpha,alpha-13c2,99 atom % 13 c | 1,3-Bis[(~13~C)methyl]benzene | J-003655 | DTXSID40583887 | 1,3-Di((113C)methyl)benzene | M-XYLENE-ALPHA,ALPHA/'-13C2

Storage

Room temperature

Specifications

Sinonimi

m-Xylene-dimethyl-13C2 | m-Xylene-(dimethyl-13C2), 99 atom % 13C | m-Xylene-alpha,alpha-13c2,99 atom % 13 c | 1,3-Bis[(~13~C)methyl]benzene | J-003655 | DTXSID40583887 | 1,3-Di((113C)methyl)benzene | M-XYLENE-ALPHA,ALPHA/'-13C2

Specifiche e purezza

≥99 atom% 13C

Condizioni di conservazione di stoccaggio

Room temperature

Purezza

≥96%(SDS-PAGE)

Nomi e identificatori

Sorrisi canonici

CC1=CC(=CC=C1)C

IUPAC Name

1,3-di((113C)methyl)benzene

InChIKey

IVSZLXZYQVIEFR-ZDOIIHCHSA-N

INCHI

1S/C8H10/c1-7-4-3-5-8(2)6-7/h3-6H,1-2H3/i1+1,2+1

Isomeri SMILES

[13CH3]C1=CC(=CC=C1)[13CH3]

Numero UN

1307

Peso molecolare

108.15

Reaxy-Rn

605441

Reaxys-RN_link_address

https://www.reaxys.com/reaxys/secured/hopinto.do?context=S&query=IDE.XRN=605441&ln=

Proprietà chimiche e fisiche

• Indice di rifrazione: n20/D 1.497 (lit.)
• Punto di infiammabilità (°F): 77.0 °F - closed cup
• Punto di infiammabilità (°C): 25 °C - closed cup
• Punto di ebollizione (°C): 138-139℃ (lit.)
• Punto di fusione (°C): -48℃ (lit.)

Application Protocols

No item-specific validated protocols are provided. The following are general, non-binding guidelines for common analytical use as an internal standard (IS) in GC/MS; adjust to your method and refer to your governing SOPs.

Example workflow (literature-informed):

• Stock preparation: Prepare a gravimetric stock (e.g., 1000 µg/mL) in isooctane or another compatible solvent. Record temperature and density if volumetric steps are used.
• Calibration standards: Spike a constant IS amount into each calibrator and sample to achieve an IS response comparable to target analyte levels. Typical IS final concentrations are 1–1000 ng/mL depending on matrix and detector.
• Instrument: Monitor characteristic ions corresponding to m-xylene and the +2 m/z shifted ¹³C₂ analog (e.g., selected ion monitoring in EI GC/MS). Verify lack of isotopic cross-talk.
• Quantitation: Use the ratio of analyte/IS peak areas with a calibration curve constructed under identical conditions. Confirm linearity and absence of matrix effects; evaluate recovery via matrix-matched spikes.

Quality controls:

• Check isotopic purity and chemical purity at receipt via GC/MS and, if needed, ¹³C NMR.
• Evaluate stability of working solutions over the intended holding time; store sealed, minimize headspace to reduce volatilization.

Item-specific method parameters are not provided; consult the CoA and your internal method validation documentation.

Biological Roles

This product is intended strictly for research use. No biological activity is implied.

General/literature context (parent compound m-xylene):

• Absorption and distribution: m-Xylene is readily absorbed by inhalation and dermal exposure; distributes to lipid-rich tissues due to hydrophobicity.
• Metabolism: Primarily via cytochrome P450-mediated benzylic oxidation to 3-methylbenzyl alcohol, subsequently to 3-methylbenzoic acid (m-toluic acid), and conjugation to 3-methylhippuric acid for renal excretion.
• Biomonitoring: Urinary 3-methylhippuric acid is used as a biomarker of occupational exposure to m-xylene.

Role of ¹³C labeling in biosciences (research/literature):

• Tracer studies: ¹³C at the methyl carbons enables unambiguous tracking of metabolic incorporation and kinetics using isotope-ratio MS or LC–HRMS.
• Environmental fate: Isotope tracing helps delineate biodegradation pathways in soil and wastewater microcosms (e.g., differentiating volatilization losses from biotransformation).

Note: These are general literature insights about unlabeled m-xylene metabolism. They are provided for conceptual planning only and do not constitute any medical or clinical guidance.

Buffer Applications

Not typically applicable. m-Xylene-(dimethyl-¹³C₂) is a nonpolar aromatic hydrocarbon and is not used to formulate aqueous buffers or pH control systems. For practical use, refer instead to the Solvent Selection and Reaction & Applications sections for guidance on analytical spiking and tracer applications.

Green Alternatives

Because this product is primarily an isotopically labeled standard/tracer, “green replacement” is generally not applicable for its core function. However, where m-xylene serves as a process solvent or diluent in method development, greener alternatives can sometimes substitute. Consider the trade-offs below (literature perspective):

| Option | Greenness notes | Performance trade-offs | |---|---|---| | 2-Methyltetrahydrofuran (2-MeTHF) | Biorenewable feedstock, better EHS profile than aromatics; forms azeotropes with water aiding workups | Different polarity; may alter selectivity/yields in EAS and metal-catalyzed reactions; peroxide-former (monitor). | | Cyclopentyl methyl ether (CPME) | Lower peroxide tendency than THF, wider liquid range; reduced VOC reactivity | More expensive; different solvency for aromatics; peroxide monitoring still needed. | | Toluene | Widely available, lower bp → easier removal, somewhat improved EHS vs xylenes | Higher volatility → increased VOC emissions; similar toxicity/flammability class. | | Bio-based ethyl acetate | Low toxicity, biodegradable, green score favorable | Much more polar; not a substitute for aromatic solvency; may not dissolve hydrophobic polymers or support EAS. |

Guidance:

• For analytical isotope-dilution, the labeled analog cannot be replaced without compromising measurement accuracy.
• For ancillary tasks (rinsing/dilution), consider isooctane, heptane, or ethyl acetate depending on matrix compatibility and EHS policies.

Pharmaceutical Uses

No therapeutic or clinical use is implied. For research and manufacturing analytics, isotopically labeled aromatics can play roles such as:

• Internal standards for residual solvent analysis: m-Xylene is a Class 2 residual solvent per ICH Q3C; a ¹³C-labeled analog can serve as a stability-robust internal standard for GC/FID or GC/MS quantitation during pharmaceutical process development and QC.
• Process tracing: Assess losses and partitioning of aromatic impurities during extraction, crystallization, or drying operations using isotope-dilution balances.
• Materials R&D: ¹³C-labeled aromatics are occasionally incorporated as tracers in polymer or coating formulations to study diffusion, migration, or aging by solid-state NMR or ToF-SIMS.

Compliance and documentation:

• Use with appropriate reference documentation (CoA specifying isotopic and chemical purity) to support method validation parameters (specificity, accuracy, linearity, robustness) where isotope-dilution is employed.
• Ensure segregation of analytical standards from GMP production materials; this product is for research use only (per product data).

Physical Properties

Item-specific specifications for this lot are not provided; consult the CoA/Spec Sheet for authoritative numbers.

• Appearance (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Density (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Refractive index (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (item-specific): Not specified for this item; refer to CoA/Spec Sheet.

Literature/typical properties for unlabeled m-xylene (for guidance only; isotopic substitution minimally affects bulk properties):

• Boiling point: ~139–140 °C (literature)
• Melting point: ~−47 to −48 °C (literature)
• Density: ~0.86 g/mL at 20 °C (literature)
• Refractive index (n20 D): ~1.495 (literature)
• LogP (octanol/water): ~3.2 (literature)
• Vapor pressure: ~8–10 mmHg at 25 °C (literature)
• Water solubility: ~160–200 mg/L at 25 °C (literature)

Notes for practitioners:

• Isotopic labeling with ¹³C₂ at the methyl positions does not materially change volatility or solvency in most separations; retention times in GC are generally within the same window as unlabeled m-xylene, with predictable m/z shifts in EI/CI MS.
• Physical constants above should be used as planning guidance only; verify item-specific values on the CoA if method-critical (e.g., density-based spiking, calibration gravimetry).

Quality and Grades

• Grade/Purity (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Isotopic enrichment (item-specific): Not specified for this item; refer to CoA/Spec Sheet.

Context for this product class (isotopically labeled aromatics):

• Isotopic grade typically specifies atom% ¹³C at each labeled site and overall chemical purity (GC area %, residual solvents, water). High-precision MS/NMR applications often require ≥98–99 atom% ¹³C at labeled carbons and ≥98–99% chemical purity; verify on the CoA for this SKU.
• Trace impurity profile can include other xylene isomers, toluene/ethylbenzene, and residual synthetic reagents/solvents. For quantitative MS, isotopic purity relative to the unlabeled analog is critical to minimize isotopic interference.

Implications of stabilizers/additives:

• Aromatic hydrocarbons like m-xylene are generally supplied neat without stabilizers. If any stabilizer is present, it will be declared on the CoA; absence of declaration typically indicates none added.

Fit-for-purpose guidance:

• Environmental GC/MS (EPA 8260/524 variants), occupational monitoring, or combustion/atmospheric studies usually demand isotope-dilution internal standards with documented isotopic composition; confirm the enrichment certificate matches your method’s calculation model.
• NMR applications: ¹³C labeling at the methyl carbons enhances site-specific signal; solvent background should be deuterated for lock/shim if using NMR (this product itself is not deuterated).

Reaction and Applications

Primary use cases center on isotopic tracing and quantitative analysis rather than stoichiometric transformation:

Analytical and mechanistic applications:

• Isotope-dilution GC/MS or LC/MS: spike samples with a known amount of m-xylene-(dimethyl-¹³C₂) to quantify native m-xylene in environmental air canisters, soil extracts, fuels, and process streams. The ¹³C₂ label provides a clean mass offset with identical chromatographic behavior.
• ¹³C NMR enhancement at methyl positions: facilitates assignment and dynamic studies (e.g., relaxation, NOE transfer involving benzylic carbons) when used in appropriate NMR solvents.
• Reaction tracing: follow fate of benzylic carbons during oxidation (to 3-methylbenzoic acid/3-methylbenzyl alcohol), halogenation (benzylic bromides), or radical processes; the ¹³C label confirms carbon origin in products by MS or 2D NMR.

Transformations typical of m-xylene (literature guidance; apply judiciously to labeled material):

• Electrophilic aromatic substitution (EAS): nitration, sulfonation, Friedel–Crafts acylation/alkylation; directing effects from the two methyl groups favor substitution at positions 2 and 4 (ortho/para relative to each methyl, translating to 2,4,6-trisubstituted patterns overall).
• Benzylic functionalization: radical bromination (NBS/AIBN, light), oxidation to aldehydes/acids (e.g., KMnO4, Co/Mn/Br-catalyzed aerobic oxidation), and side-chain coupling.

Practical tips:

• When used as an internal standard, prepare gravimetric stock solutions in a stable solvent (e.g., isooctane, methanol with caution due to limited miscibility) and store in crimped amber vials to minimize evaporation.
• Confirm isotopic purity and absence of unlabeled m-xylene carryover to avoid bias at low analyte concentrations.

Reaction Conditions

The labeled compound follows the chemistry of m-xylene; representative conditions below are literature generalities to assist planning. Optimize and verify for isotopic integrity.

• Benzylic bromination (radical):
  • Typical: NBS (1.1–1.5 equiv), AIBN (cat.) or photolysis (hv), CCl4 or CH2Cl2 solvent, reflux or RT–reflux, 2–8 h. Benzylic monobromination favored; yields 60–85% (literature ranges). ¹³C label retained at the benzylic carbon.
• Side-chain oxidation to acids:
  • KMnO4 in alkaline aqueous acetone/toluene biphasic; reflux until decolorization; work up with acidification → 3-methylbenzoic acid or deeper oxidation to isophthalic acid depending on conditions. Alternatively, Co/Mn/Br-catalyzed aerobic oxidation in acetic acid at 120–180 °C (industrial-style) affords high conversions.
• Electrophilic aromatic nitration:
  • HNO3/H2SO4 mixed acid at 0–5 °C to control exotherm; regioisomeric distribution influenced by two methyl activators; subsequent separation required. Work under fume hood with rigorous temperature control.
• Friedel–Crafts acylation:
  • Acyl chloride (1.1–1.5 equiv), AlCl3 (1.2–2 equiv), DCM or CS2, 0 °C to RT, 1–6 h. Quench carefully; labels remain at methyl (benzylic) carbons.

Analytical handling:

• GC/MS internal standard use commonly employs stock solutions at 100–1000 µg/mL in isooctane; verify response factors and isotopic purity before calibration. Store stocks in crimp-sealed amber vials to minimize evaporation and adsorption.

Safety and Handling

Item-specific hazard classifications are not supplied here; always consult the product SDS for definitive safety information.

• GHS classification (item-specific): Not specified for this item; refer to SDS.
• Signal word / H-statements / Pictograms (item-specific): Not specified for this item; refer to SDS.

General hazards (literature, based on m-xylene):

• Highly flammable liquid and vapor; harmful by inhalation and skin contact; may cause drowsiness/dizziness; irritant to eyes/skin.
• Aspiration hazard if swallowed and enters airways.

Handling and PPE (good laboratory practice):

• Use in a certified chemical fume hood to control vapors.
• Wear chemical-resistant gloves (e.g., nitrile), lab coat, and splash goggles. Change gloves regularly due to permeation by aromatic hydrocarbons.
• Keep away from heat, sparks, open flames, and hot surfaces. Use explosion-proof equipment and intrinsically safe tools where applicable.

Storage and incompatibilities:

• Storage condition (item-specific): Room temperature (from product data). Store tightly closed in a flammables cabinet.
• Keep away from strong oxidizers (e.g., nitric acid, peroxides), strong acids, and halogens.
• Ground/bond containers during transfer to prevent static accumulation.

First aid (summary; follow SDS/local procedures):

• Inhalation: Move to fresh air; seek medical attention if symptoms persist.
• Skin: Remove contaminated clothing, wash with soap and water.
• Eyes: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do.
• Ingestion: Do not induce vomiting; seek medical attention immediately (aspiration risk).

Solvent Selection

This item is most often used as an isotopic tracer or internal standard rather than as a bulk reaction solvent. Nevertheless, its solvency profile mirrors that of m-xylene (literature characteristics):

• Polarity class: nonpolar, aromatic hydrocarbon; weak hydrogen-bond acceptor, not a donor.
• Dielectric constant: ~2.3 at 20 °C (literature, m-xylene).
• Miscibility: immiscible with water; miscible with most organics (ethers, esters, ketones, aromatics, chlorinated solvents). Limited miscibility with highly polar protic solvents.
• Boiling range: ~139–140 °C (literature), useful for medium-high temperature processes if used as a medium (rare for the labeled form due to cost).

When to choose it (analytical/trace-level use):

• As an internal standard for quantifying m-xylene by GC/MS; isotopic match ensures co-elution with distinct mass channels (Δm/z from ¹³C₂).
• As a tracer in reaction monitoring to assess mass balances or volatilization losses of aromatic fractions.

Comparison (literature) with related aromatics:

| Solvent | bp (°C) | Relative polarity | Notes | |---|---:|---:|---| | m-Xylene | ~139 | very low | Higher bp than toluene; good for higher-temp work. | Toluene | ~111 | very low | More volatile; widely used general solvent. | Ethylbenzene | ~136 | very low | Similar bp; slightly different chromatographic behavior.

Note: For routine process-scale solvent needs, the unlabeled counterparts are appropriate; the labeled material is reserved for analytical or mechanistic purposes.

Storage and Reconstitution

• Storage conditions (item-specific): Room temperature (per product data). Store in a tightly sealed container, protected from ignition sources, preferably in a flammables cabinet.
• Shipped in (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Appearance (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Reconstitution: Not applicable; supplied neat unless otherwise stated. If preparing stock solutions, use dry, compatible solvents (e.g., isooctane, hexane, or other GC-grade solvents) and record concentrations gravimetrically.
• Handling notes:
  • Minimize headspace and use crimped caps/Teflon-lined septa to limit evaporation loss.
  • For long-term storage of dilute solutions, prefer amber glass at consistent temperature; avoid plasticware that may sorb aromatics.
  • Do not freeze aqueous mixtures; phase separation and pressure buildup may occur.

Always refer to the product’s CoA and SDS for container type, lot-specific stability, and any special precautions. Research use only (per product data).

Structure and Identity

m-Xylene-(dimethyl-¹³C₂) is an isotopically labeled derivative of m-xylene (1,3-dimethylbenzene) in which the carbon atoms of both methyl substituents are ¹³C-enriched. This retains the parent aromatic framework while enabling precise isotope tracing by MS and enhanced visibility at the methyl positions in ¹³C NMR.

• SKU: M473815
• Product name: m-Xylene-(dimethyl-¹³C₂)
• CAS: 117713-57-2
• PubChem CID: 16213348
• InChIKey (from product data): 151783
• Molecular formula (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight (item-specific): Not specified for this item; refer to CoA/Spec Sheet.
• SMILES (item-specific): Not specified for this item; refer to CoA/Spec Sheet.

Structural description (general/literature):

• Core: benzene ring bearing two methyl groups in the meta (1,3-) relationship.
• Isotopic labels: the carbon atoms of each methyl group are ¹³C isotopes; hydrogen atoms are protium (non-deuterated) unless otherwise specified.
• 2D features: three adjacent aromatic C–C bonds between substituents; two benzylic positions (methyls) separated by one ring carbon (meta).

Representative isotopically annotated SMILES (literature example, not item-specific): c1cc(C[13CH3])cc(C[13CH3])c1 (placement meta).

Synthetic Utility

While cost generally discourages stoichiometric use, m-xylene-(dimethyl-¹³C₂) can be strategically employed in synthesis to embed ¹³C labels into downstream structures derived from the methyl carbons or to validate mechanisms.

Transformational opportunities (literature-informed):

• Benzylic functionalization to transfer the ¹³C label:
  • Radical bromination (NBS/hν or AIBN) → 3,5-dimethylbenzyl bromide derivatives; subsequent substitution provides ¹³C-labeled benzyl ethers, amines, or nitriles.
  • Oxidation (e.g., KMnO4; or Co/Mn/Br-catalyzed aerobic systems) → 3-methylbenzoic acid or isophthalic acid derivatives with ¹³C retained at the carboxyl carbon if side-chain oxidation is complete.
• Ring electrophilic substitution (Friedel–Crafts acylation/alkylation): Introduce additional substituents while maintaining ¹³C labels at the benzylic positions; useful to trace side-chain fate under harsh conditions.
• Lithiation of benzylic positions (under strong base, e.g., sec-BuLi at low temperature) followed by quench can map isotope scrambling or confirm site selectivity via ¹³C NMR.

Mechanistic studies:

• Kinetic isotope effects are minimal for ¹³C, but position-specific ¹³C allows product apportionment in competing pathways using ¹³C NMR integration or HRMS isotope pattern deconvolution.

Note: Confirm isotopic integrity post-transformation (e.g., quantitative ¹³C NMR, GC–HRMS) to ensure labels were not lost via decarboxylation or disproportionation.

Target Specificity

Not applicable. This product is a small-molecule isotopically labeled hydrocarbon, not a biological targeting reagent. No antigen/epitope specificity, clone, isotype, or species reactivity data are relevant.

Domande frequenti

What is the isotopic enrichment of this product?

This product is isotopically enriched to ≥99 atom% carbon-13. Isotopic enrichment is a separate specification from chemical purity — a labelled compound has both. Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at room temperature.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 117713-57-2, the molecular formula is C8H10, and the molecular weight is 108.15 g/mol. InChIKey IVSZLXZYQVIEFR-ZDOIIHCHSA-N.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.