METHYL NAPHTHALENE-2-SULFONATE

CAS Number: 5138-53-4.
EC Number: A reliable EC number for this exact ester was not verified in the reviewed sources.
Molecular Formula: C11H10O3S.
Molecular Weight: Approximately 222.26 g/mol.
Boiling Point: A reliable experimental value with a stated pressure was not verified.
Melting Point: A sufficiently supported experimental value was not verified for inclusion here; the compound has been isolated as a white solid in synthetic literature.
Viscosity: No verified numerical value is assigned; solid material and its solutions require different descriptions.
Density: A reliable experimental value with temperature and physical-form information was not verified.

COMMON PRODUCT AND CHEMICAL NAMES

Methyl naphthalene-2-sulfonate
Methyl 2-naphthalenesulfonate
Methyl naphthalene-2-sulphonate
Naphthalene-2-sulfonic acid methyl ester
2-Naphthalenesulfonic acid, methyl ester
MeONs, the abbreviation used in relevant kinetic studies

DESCRIPTION AND CHEMICAL IDENTITY

Methyl naphthalene-2-sulfonate is a discrete small molecule rather than a polymeric condensate. Its composition contains one sulfur atom, three oxygen atoms and no sodium or other metal counterion.
The word methyl identifies the alkyl portion of the sulfonate ester. It does not describe a methyl substituent on the naphthalene ring, and the locant 2 identifies the position of the sulfonyl substituent on that ring.
Methyl naphthalene-2-sulfonate can be represented as C10H7-SO2-OCH3. This structural description is useful when checking a catalogue entry, certificate or synthesis record because several chemically different compounds can have deceptively similar names.
Naphthalene-2-sulfonic acid and sodium naphthalene-2-sulfonate are related acid and salt forms, but neither is an exact synonym for this methyl ester. Their melting behavior, aqueous properties and reactivity must remain associated with their own identities.

The constitutional isomer 2-naphthyl methanesulfonate has the connectivity CH3-SO2-O-naphthyl. Although it has the same elemental formula, its attachment pattern differs, so its name and physical data should not be substituted for those of methyl naphthalene-2-sulfonate.
Likewise, methyl naphthalene-1-sulfonate is a positional isomer, and ring-alkylated methyl naphthalene sulfonate esters are substituted derivatives. Their research results can support a comparison but cannot automatically establish a property of the unsubstituted 2-isomer.
For an enquiry about methyl naphthalene-2-sulfonate to Ataman Chemicals, the complete name and CAS number should be supplied together. A structure drawing or structural identifier is helpful where an existing specification uses an abbreviated or ambiguous name.

MOLECULAR STRUCTURE AND REACTIVITY

The naphthalene portion of methyl naphthalene-2-sulfonate provides a fused aromatic framework, while the sulfonate ester group provides the reactive methyl-oxygen connection. The intact molecule has no formal ionic charge and no free sulfonic acid proton.
In the substitution reactions documented for methyl naphthalene-2-sulfonate, a nucleophile can attack the methyl carbon and displace the naphthalene-2-sulfonate group. This reaction transfers the methyl group; it does not require substitution of an aromatic carbon on the naphthalene ring.
A simplified representation is Nu + CH3-O-SO2-C10H7 giving a methylated nucleophile and naphthalene-2-sulfonate. The charges and final protonation state depend on the nucleophile and reaction conditions.
For a tertiary amine, methyl transfer can give a quaternary ammonium cation with naphthalene-2-sulfonate as counterion. For a halide, the corresponding methyl halide can be generated under conditions that permit the substitution.

These reactions explain why methyl naphthalene-2-sulfonate is useful as a kinetic substrate. The observed rate responds to the availability of the nucleophile and to the environment experienced by the substrate.
Hydrolysis is another transformation investigated experimentally. Water or hydroxide participates in conversion of methyl naphthalene-2-sulfonate, and the rate depends on the medium rather than being a universal measure of storage stability.
The general structural explanation does not establish that every nucleophile reacts efficiently or that a particular synthetic conversion is selective. Solvent, temperature, reagent concentrations and competing reactions must be assessed for the intended operation.

PHYSICAL AND CHEMICAL PROPERTIES

The numerical information below distinguishes molecular calculations and published characterization from an unverified commercial release specification. It should not be treated as a complete certificate of analysis for material supplied by Ataman Chemicals.
Molecular Formula: C11H10O3S for the neutral, unlabeled compound.
Average Molar Mass: Approximately 222.26 g/mol, calculated from the elemental composition using conventional atomic weights.
Neutral Monoisotopic Mass: Approximately 222.0351 Da, calculated using the most abundant isotopes of carbon, hydrogen, oxygen and sulfur. This is different from an average molecular weight or the mass-to-charge ratio of an ionized adduct.
Elemental Composition: Calculated mass fractions are approximately 59.44% carbon, 4.54% hydrogen, 21.60% oxygen and 14.43% sulfur; small rounding differences are expected.
Formal Charge: Zero for the intact methyl ester.
Structural Units: One naphthalene system, one sulfonate ester group and one O-methyl group; there is no polymer molecular-weight distribution intrinsic to this defined structure.
Physical Appearance: A synthetic patent example reports isolation as a white solid. That observation describes the reported sample rather than a universal color specification for every commercial grade.
Proton NMR Characterization: One published synthetic example records an O-methyl signal near 3.79 ppm and aromatic signals approximately between 7.6 and 8.5 ppm, measured at 400 MHz in deuterated chloroform. Exact shifts and splitting should be compared with the complete reference spectrum under matching conditions.
Proton Count: The ideal structure contains seven aromatic hydrogens and three methyl hydrogens. The expected 7:3 integral relationship is a structural check, not a stand-alone quantitative assay.
Solvent Evidence: The cited NMR measurement demonstrates preparation of a sample in deuterated chloroform, and a separate synthetic use dissolves the reagent in ethyl acetate. Neither observation establishes a saturation solubility or compatibility with every organic solvent.
Water Behavior: Published studies examine reactions in aqueous and micellar media. Such use does not establish unlimited water solubility or persistence of an unchanged ester during prolonged contact with water.
Melting Point: No adequately corroborated numerical value is assigned in this profile. Values for the parent sulfonic acid, sodium salt or constitutional isomer must not be imported.
Boiling Point: No reliable experimental value with pressure was verified. A predicted boiling temperature would require clear labeling and would not demonstrate thermal suitability for distillation.
Density: No verified numerical value is assigned. Crystal density, powder bulk density and solution density would describe different measurements.
Viscosity: No verified neat-material or solution value with defined conditions was located. Solution concentration, solvent, temperature and method would need to accompany any reported result.
pH: No intrinsic pH is assigned to the neat neutral ester. A measured value for a water-containing preparation would depend on its composition, preparation history and possible reaction products.
Hydrolytic Stability: Hydrolysis is experimentally documented, but a universal hydrolysis half-life is not assigned because rates change with medium and conditions.
Flash Point and Decomposition Temperature: No verified numerical values are assigned. Operational fire and temperature limits must come from appropriate current product information and process assessment.
Purity and Moisture: No universal minimum assay or maximum water content is claimed. These are grade- and batch-dependent analytical requirements.

INTERPRETING SPECTRAL AND ANALYTICAL DATA

Identity control for methyl naphthalene-2-sulfonate is especially important because related sulfonic acids, salts and sulfonate esters can be confused by name. A formula or molecular weight alone cannot distinguish the methyl ester from a constitutional isomer having the same composition.
Proton NMR is useful because the O-methyl group and aromatic region provide complementary structural information. Integration and the complete aromatic pattern should be interpreted together rather than accepting one peak as sufficient identification.
Chromatographic purity and chemical identity answer different questions. A dominant chromatographic peak is not proof that the peak corresponds to the intended 2-isomer without a suitable identification method or reference.

Likewise, UV area percentage is not automatically a mass assay. Detector response, wavelength, impurity absorption and the possibility of undetected constituents affect the relationship between peak area and composition.
Mass spectrometry can support the molecular composition, but the observed ion must be identified correctly. The neutral monoisotopic mass is not interchangeable with a protonated, sodiated or fragmented ion.
For a reaction-kinetics application, small amounts of acidic, basic or nucleophilic contamination may matter even when they contribute little to a chromatographic area result. The analytical requirements should therefore reflect the sensitivity of the intended experiment.
A proposed quality specification for methyl naphthalene-2-sulfonate should link identity, assay, relevant impurities and water content to the actual use. No arbitrary analytical limits are inferred from the generic chemical name.

APPLICATIONS IN NUCLEOPHILIC SUBSTITUTION RESEARCH

Methyl naphthalene-2-sulfonate is a documented substrate for studying bimolecular nucleophilic substitution. Its defined methyl group and aromatic sulfonate leaving group allow investigators to examine methyl transfer under different reaction conditions.
Published work has compared reactions involving halide ions and several other nucleophiles. Amine reactions have also been investigated, providing a way to compare the behavior of neutral and ionic reactants in the same broad substrate family.
The experimental objective is usually more specific than simply obtaining conversion. Researchers may ask whether a change in observed rate results from the local nucleophile concentration, substrate partitioning or a change in the chemical reaction step.

Methyl naphthalene-2-sulfonate is useful in that setting because the same substrate can be studied across different organized aqueous environments. Keeping the substrate constant helps focus a comparison on the medium or surfactant variable being investigated.
However, reaction-rate comparisons require matching temperature, reagent concentrations and measurement methods. A rate enhancement reported in one micellar system should not be advertised as an inherent catalytic property of the ester itself.
For research supply, identity and reproducibility can therefore be more important than a broad claim of industrial dispersing performance. Methyl naphthalene-2-sulfonate is consumed or transformed during the model reaction rather than serving as a reusable catalyst.

APPLICATIONS IN MICELLAR CATALYSIS AND INTERFACIAL CHEMISTRY

A substantial part of the documented use of methyl naphthalene-2-sulfonate concerns reactions in surfactant micelles. The ester serves as a substrate interacting with an organized medium; the surfactant provides the micelles.
Micellar reaction behavior can reflect two distinct effects. Reactants may become concentrated near one another at an interface, while the local environment can also change the rate constant of the chemical step.
A measured acceleration therefore does not by itself prove that the reaction step is intrinsically faster at the interface. Partitioning of the substrate and availability of the nucleophile need to be considered alongside the observed rate.
Studies using cationic surfactants have examined the influence of headgroup structure and hydrophobic substituents. These comparisons help investigate how molecular environment affects the meeting of a neutral ester with an ionic reactant.
In practical research planning, changing surfactant concentration may change more than the number of aggregates. It can alter reactant distribution and, in some systems, aggregate structure.
The value of this application is mechanistic information about organized reaction media. It does not establish that methyl naphthalene-2-sulfonate is itself a detergent, dispersant, emulsifier or other bulk formulation surfactant.

APPLICATIONS IN ANION BINDING AND ION COMPETITION STUDIES

Reactions of methyl naphthalene-2-sulfonate with bromide or iodide have been used to investigate the availability of nucleophilic anions in micellar environments. The substrate provides a chemically responsive probe of anion behavior near the interface.
Research on sulfobetaine micelles has shown that added ions can modify the observed reaction. For example, studies describe inhibition when an added competing anion displaces reactive anions from the relevant interfacial region.
This allows reaction kinetics to contribute information about ion competition rather than relying only on bulk salt concentration. The chemically relevant concentration near a micelle can differ from the concentration calculated for the entire solution volume.
The interpretation remains model-dependent. A rate response should be connected to the specified surfactant, competing ions and distribution assumptions rather than treated as a universal calibration for anion binding.
For a research programme, methyl naphthalene-2-sulfonate can therefore be useful as one component of a comparative measurement strategy. Independent physical measurements and appropriate controls strengthen the interpretation of the kinetic result.

APPLICATIONS IN MIXED MICELLES AND AGGREGATE MORPHOLOGY

Methyl naphthalene-2-sulfonate has also been investigated in mixed surfactant systems. Published work describes the bromide reaction in mixtures of a cationic surfactant and a nonionic phosphine oxide surfactant.
Such a comparison can separate the effects of changing interfacial composition from those of changing substrate identity. The added nonionic component modifies the micellar environment while the reacting ester remains the same.
Research using dimeric, or gemini, surfactants has examined reaction behavior across changes in concentration and in the presence of additives. These studies relate kinetics to the distribution of reactants and to changes in aggregate morphology.
This application is relevant when a researcher needs to distinguish a chemical-medium effect from a structural transition in the assembly. A simple concentration-versus-rate plot may otherwise combine several different physical processes.
A published result for one additive cannot be generalized to all cosolvents or mixed micelles. Additives differ in whether they remain predominantly in bulk water, enter the aggregates or distribute between the two environments.

APPLICATIONS IN HYDROLYSIS AND STRUCTURE-REACTIVITY COMPARISONS

Spontaneous hydrolysis and hydroxide reactions of methyl naphthalene-2-sulfonate are documented in the micellar-kinetics literature. These transformations provide a reference for examining the role of water, ionic environment and interfacial conditions.
Comparative studies have included derivatives bearing additional alkyl groups on the naphthalene ring. Those derivatives retain a related reaction center while changing the hydrophobic structure available to interact with the medium.
This is useful for studying whether a structural change primarily affects binding, location in the aggregate or the intrinsic reactivity of the reacting group. It also demonstrates why a rate measurement should not be interpreted solely from the apparent hydrophobicity of a compound.
Methyl naphthalene-2-sulfonate can serve as a baseline substrate in such comparisons, provided that the exact structure and purity are established. Data for an alkyl-substituted derivative should remain associated with that derivative rather than being presented as a property of the parent ester.
These studies concern defined experimental conditions. They do not provide a single room-temperature storage half-life or prove that an aqueous stock remains unchanged throughout an unrelated process.

APPLICATIONS IN METHYLATION AND QUATERNARY SALT SYNTHESIS

The chemical ability of MeONs to transfer a methyl group has a documented preparative example in patent literature. A tertiary amino ester is reacted with methyl naphthalene-2-sulfonate to form a quaternary ammonium product carrying naphthalene-2-sulfonate as counterion.
This use illustrates the structural logic of the reagent. The methyl portion is transferred to nitrogen, while the aromatic sulfonate portion becomes the counterion of the product.
Selection of a methylating reagent can therefore influence both the substitution achieved and the resulting salt form. It does not follow that MeONs is the preferred reagent for every amine or that the isolated product will have predictable crystallization behavior.

The documented example supports a specialty synthesis application rather than a universal reaction recipe. The chosen amine, solvent, process temperature, isolation route and impurity profile require their own development.
Any therapeutic properties discussed for a resulting quaternary compound belong to that product and its evidence. They must not be assigned to methyl naphthalene-2-sulfonate itself.
A supply enquiry for methyl naphthalene-2-sulfonate for this purpose should describe the intended transformation and relevant quality constraints. This is more informative than classifying the reagent broadly as a pharmaceutical ingredient.

PREPARATION AND PROCESS CONSIDERATIONS

Synthetic literature describes preparation of methyl naphthalene-2-sulfonate from naphthalene-2-sulfonyl chloride and methanol. A published example isolates the product as a white solid and characterizes it by proton NMR.
That route establishes a documented preparation pathway. It should not be interpreted as the manufacturing process, purification procedure or impurity specification of every commercial material.
For process development, starting-material identity is important because positional-isomer contamination can complicate final identification. Residual reagents, reaction products and solvent can also affect the suitability of a batch for sensitive kinetic or synthetic work.
A laboratory preparation does not establish plant-scale heat transfer, reaction calorimetry, off-gas behavior or isolation performance. Scale-up requires assessment of the actual procedure and equipment.
Stock-solution preparation for methyl naphthalene-2-sulfonate deserves separate attention. The selected solvent should dissolve the required concentration without causing unacceptable reaction or introducing interfering constituents.
When a stock is used for quantitative kinetics, concentration and preparation history should be recorded. A freshly prepared solution and one exposed to water or nucleophiles for an extended period may not represent the same amount of unchanged ester.

SELECTION AND LIMITATIONS

Methyl naphthalene-2-sulfonate is most clearly supported as a specialty chemical for reaction studies and selected methylation chemistry. The reviewed primary evidence does not establish it as a general water-treatment agent, antimicrobial additive, cosmetic ingredient or polymeric dye dispersant.
The neutral ester structure of methyl naphthalene-2-sulfonate is central to its research role. Substitution of a sodium naphthalene sulfonate or a formaldehyde condensate would change the chemical system rather than provide a chemically equivalent grade.
Other methyl sulfonate esters can offer alternative substrate structures for a comparison. Their selection should follow the purpose of the experiment, including the desired leaving group, medium interaction and analytical detection method.

No general claim is made that this reagent reacts faster, is safer or gives higher yield than methyl iodide, methyl methanesulfonate or another methylating agent. Those comparisons require a defined transformation and suitable evidence.
For procurement, distinguish research identity confirmation from a claim of certified reference-material status. A material used as a laboratory comparison substance is not automatically a certified analytical standard.
Ataman Chemicals enquiries should state the intended use, required amount, identity method, assay basis and any critical impurity limits. Pack sizes, availability and offered documentation should be confirmed for the proposed supply rather than assumed.

STARTING FORMULATION APPROACHES FOR METHYL NAPHTHALENE-2-SULFONATE

The following examples illustrate laboratory solution and analytical development approaches for Methyl Naphthalene-2-Sulfonate. They are not validated commercial recipes, production instructions, or final formulations confirmed to comply with applicable regulations. No finished-product use level is established by these examples.
Methyl Naphthalene-2-Sulfonate, also known as methyl 2-naphthalenesulfonate or naphthalene-2-sulfonic acid methyl ester, is the neutral sulfonate ester identified by CAS 5138-53-4, molecular formula C11H10O3S, and molecular weight approximately 222.26 g/mol. Confirm this identity against the supplier's certificate and safety data sheet before development. Its properties must not be inferred from those of naphthalenesulfonic acid salts or sulfonated dispersant polymers.
The proposed concentrations and conditions are illustrative screening points requiring experimental verification. Solubility, solution stability, assay, and analytical response must be established for the actual material. Use documented purity or certified assay values where applicable; chromatographic area purity alone is not necessarily a quantitative mass assay. Perform a task-specific safety assessment because sulfonate ester reactivity, including potential alkylating reactions, is relevant to handling and compatibility.

EXAMPLE 1: METHYL NAPHTHALENE-2-SULFONATE SOLVENT AND CONCENTRATION SCREENING

Objective: To identify a suitable laboratory solvent and working concentration for preparing reproducible solutions of Methyl Naphthalene-2-Sulfonate.

Starting components:

Methyl Naphthalene-2-Sulfonate: target concentrations of approximately 1, 5, and 10 mg/mL

Candidate solvents: analytical-grade acetonitrile, ethyl acetate, and acetone, tested separately

Preparation temperature: select one setpoint within approximately 20–25 °C and keep constant

Mixing time, vial material, sample volume, and observation schedule: keep constant

Initial additives: omit acids, bases, salts, and surfactants

These target concentrations do not imply that complete dissolution will occur in every solvent. Solvent selection must consider both physical solubility and chemical stability, as well as the requirements of the next analytical or laboratory step.

Application approach:

Confirm the identity and documented assay of Methyl Naphthalene-2-Sulfonate and use the same material lot throughout the comparison.
Weigh appropriate small quantities into clean, dry, compatible vials and add measured solvent volumes.
Mix under the defined conditions without heating solely to force dissolution.
Record whether each preparation is clear, cloudy, partially dissolved, or visibly precipitated.
Recheck appearance after the same equilibration period and determine the dissolved concentration by a suitable calibrated method.
If filtration is used, evaluate filter compatibility and analyte recovery; do not assume the filtrate retains the nominal weighed concentration.
Compare fresh and equilibrated chromatograms to distinguish apparent dissolution from chemical change.
Select the solvent and concentration only after confirming reproducibility, acceptable recovery, and short-term stability.
Handle Methyl Naphthalene-2-Sulfonate in a suitable fume hood with eye protection and compatible gloves. Control dust, solvent vapor, and ignition sources, and collect the solutions as laboratory chemical waste.

EXAMPLE 2: METHYL NAPHTHALENE-2-SULFONATE ANALYTICAL STOCK AND CALIBRATION SOLUTION DEVELOPMENT

Objective: To prepare traceable stock and calibration solutions for developing an assay or monitoring Methyl Naphthalene-2-Sulfonate in laboratory samples.

Starting approach:

Methyl Naphthalene-2-Sulfonate stock solution: an illustrative target of approximately 1.0 mg/mL in a solvent qualified by the initial screening

Intermediate solution: approximately 100 µg/mL, prepared by a tenfold dilution of the stock

Calibration solutions: approximately 0.5, 1.0, 2.0, 5.0, and 10.0 µg/mL, prepared from the intermediate solution

Diluent: selected to preserve solubility and stability and to be compatible with the analytical method

Initial chromatographic evaluation: a suitable reversed-phase C18 column with an acetonitrile/water mobile phase

UV detection screening: approximately 214 and 254 nm, with wavelength selection confirmed experimentally

Injection volume, column temperature, mobile-phase program, and detector settings: define and keep constant within each comparison

A stock target of 1.0 mg/mL corresponds to 10.0 mg of pure-equivalent material in a final volume of 10.0 mL. Correct the weighed quantity for the documented assay where appropriate. These concentrations and detection wavelengths are method-development starting points, not a validated analytical procedure.

Application approach:

Prepare the stock using calibrated volumetric equipment and an appropriate balance, recording the material lot, weighed mass, assay correction, solvent, and final volume.
Prepare an independently weighed check solution to assess stock preparation accuracy.
Make the intermediate and calibration solutions by controlled volumetric dilution, keeping the diluent composition consistent.
Run solvent blanks and fresh calibration solutions before evaluating samples.
Assess retention, peak shape, response, carryover, and separation from solvent or matrix interference.
Compare the screened wavelengths and select conditions that provide suitable specificity and sensitivity.
Evaluate calibration behavior, replicate precision, independent-check recovery, and matrix-spike recovery where relevant.
Establish quantification limits and solution hold times experimentally before assigning reportable concentrations to unknown samples.
Use closed, compatible containers, appropriate ventilation, and suitable personal protection. Label all Methyl Naphthalene-2-Sulfonate standards with concentration, solvent, preparation date, and the provisional hold time supported by data.

EXAMPLE 3: METHYL NAPHTHALENE-2-SULFONATE SOLUTION STABILITY AND WATER-COMPATIBILITY SCREENING

Objective: To examine how water content and storage temperature affect Methyl Naphthalene-2-Sulfonate recovery and physical appearance during laboratory solution holding.

Starting approach:

Methyl Naphthalene-2-Sulfonate: approximately 0.10 mg/mL in every test solution

Solvent system A: the selected qualified organic solvent without intentionally added water

Solvent system B: the same solvent with approximately 20% water by volume, provided a single homogeneous phase is obtained

Storage conditions: approximately 2–8 °C and 20–25 °C, assessed separately

Sampling times: approximately 0, 6, 24, and 48 hours

Vial material, closure, fill volume, and light exposure: keep constant

Acids, bases, nucleophiles, and reactive additives: omit from this initial holding study

Choose a water-miscible solvent, such as acetonitrile if qualified, for the paired solvent systems. This experiment evaluates the actual preparation under the stated conditions; it does not establish a universal shelf life or the stability of the dry chemical.

Application approach:

Prepare matched test solutions from the same qualified stock and verify their starting concentrations.
Dispense separate sealed aliquots for each storage condition and sampling time to reduce repeated opening and solvent loss.
Inspect for cloudiness, precipitation, color change, and visible container interaction.
At each sampling point, use a consistent temperature equilibration and mixing procedure before analysis.
Determine Methyl Naphthalene-2-Sulfonate recovery against fresh or independently qualified standards and monitor new chromatographic peaks.
Investigate parent-compound loss separately from precipitation, adsorption, or evaporation; peak area alone does not identify the cause.
Where additional peaks appear, use suitable orthogonal analysis to investigate their identity before attributing them to a specific degradation pathway.
Select a provisional solvent system and hold time based on predefined analytical acceptance criteria, then confirm them in repeat preparations.
Use a laboratory refrigerator appropriate for the selected solvent, secondary containment, and the controls specified in the current safety data sheet. Do not discharge Methyl Naphthalene-2-Sulfonate solutions into drains.

SAFETY AND EXPOSURE CONTROL

Methyl naphthalene-2-sulfonate participates in methyl-transfer reactions with nucleophiles. This reactivity justifies controlled professional handling, but it is not a substitute for a substance-specific toxicological assessment or an authenticated hazard classification.
A sufficiently complete current safety data sheet for the exact offered product was not verified in the reviewed sources. No specific GHS category, occupational exposure limit, carcinogenicity classification or numerical toxicity value is assigned here.
Prevent inhalation of dust and avoid contact with skin and eyes. Use effective local ventilation or containment and select gloves, eye protection and protective clothing appropriate to the product documentation and operation.
A solution introduces hazards from its solvent as well as from the ester. The solvent's flammability, volatility and compatibility need to be included in the assessment.
Where a process reacts methyl naphthalene-2-sulfonate with halides or other nucleophiles, assess the products formed, including the possibility of volatile methylated products. The absence of a verified vapor-pressure value for the starting solid does not establish that the reaction system produces no hazardous vapors.
Do not classify the material as harmless because it is electrically neutral. Equally, do not copy hazard statements from a different sulfonate ester without evidence that they apply to this substance.

FIRST AID MEASURES

Eye Contact with Methyl naphthalene-2-sulfonate: Rinse immediately with plenty of clean water. Remove contact lenses if present and easy to remove, continue rinsing and obtain medical advice promptly after significant exposure or if symptoms occur.
Skin Contact with Methyl naphthalene-2-sulfonate: Remove contaminated clothing and wash the affected skin thoroughly with water and soap. Seek medical attention if irritation or other symptoms develop or persist.
Inhalation of Methyl naphthalene-2-sulfonate Dust or Solution Aerosol: Move the person to fresh air and keep them comfortable for breathing. Obtain urgent medical assistance for breathing difficulty and medical advice for persistent symptoms or substantial exposure.
Ingestion of Methyl naphthalene-2-sulfonate: Rinse the mouth and contact a poison center or medical professional for advice. Do not induce vomiting unless instructed, and give nothing by mouth to an unconscious person.
Medical Information for Methyl naphthalene-2-sulfonate Exposure: Provide the product label, available safety documentation and details of any solvent or reaction mixture involved. These general response measures do not replace the instructions supplied with the actual product.

HANDLING AND STORAGE

Handling Methyl naphthalene-2-sulfonate: Use controlled weighing and transfer procedures that minimize dust and direct contact. Avoid handling near food or drink and wash after completing the operation.
Handling Methyl naphthalene-2-sulfonate Solutions: Prepare and transfer solutions with appropriate ventilation and splash control. Assess both the reagent and solvent before selecting the container, gloves and transfer equipment.
Storage of Methyl naphthalene-2-sulfonate: Keep the container securely closed in a protected location under the conditions specified by the supplier. Avoid contamination and unnecessary exposure to moisture, because aqueous transformation of the ester is documented.

Segregation of MeONs: Prevent unintended contact with nucleophiles and other incompatible process chemicals. A material deliberately used as a methylating reagent should not share an uncontrolled storage or transfer system with reactive amines or similar reagents.
Stock Solutions of Methyl naphthalene-2-sulfonate: Label the solvent, concentration and preparation date. Establish acceptable storage time through relevant stability information rather than borrowing a shelf life from the dry material.
Shelf Life of MeONs: No universal shelf life, refrigeration temperature or required inert-gas atmosphere is assigned here. Follow the documentation for the offered grade and investigate evidence of deterioration before further use.

SPILL RESPONSE, DISPOSAL AND TRANSPORT

Spills of solid methyl naphthalene-2-sulfonate should be collected using a method that limits dust and operator contact. Avoid dispersing the powder with compressed air or allowing cleanup residues to enter drains.
For a solution spill, isolate ignition sources where relevant to the solvent and contain the release with compatible materials. The cleanup method must address the complete mixture rather than the ester name alone.
Waste may contain unchanged ester, solvents, nucleophiles and reaction products. Its classification and disposal route should be determined from the actual composition and applicable requirements.
No universal biodegradability, aquatic-safety or wastewater-treatment benefit is claimed. Experimental use in aqueous media does not demonstrate environmental acceptability of discharge.
No UN number, transport class, packing group or blanket non-dangerous-goods status is assigned without current product-specific documentation. Confirm transport requirements for the supplied form and destination.

FREQUENTLY ASKED QUESTIONS

What is Methyl naphthalene-2-sulfonate?
Methyl naphthalene-2-sulfonate is the methyl ester of naphthalene-2-sulfonic acid, a neutral aromatic sulfonate ester used in published substitution and micellar-reaction studies.

What is the CAS number of methyl naphthalene-2-sulfonate?
The chemical identity is associated with CAS 5138-53-4; the supplied product should be checked against the full name and structure.

What are the formula and molecular weight of methyl naphthalene-2-sulfonate?
The neutral compound has formula C11H10O3S and an average molecular weight of approximately 222.26 g/mol.

What does MeONs mean?
MeONs is the abbreviation used for methyl naphthalene-2-sulfonate in the relevant kinetic literature and should be defined whenever it appears in product or research records.

Is the methyl group attached to the aromatic ring?
No. The methyl group belongs to the O-methyl sulfonate ester, with the connectivity naphthyl-SO2-O-CH3.

Is 2-naphthyl methanesulfonate an exact synonym?
No. It has the connectivity CH3-SO2-O-naphthyl and is a constitutional isomer, so a matching molecular formula does not make it the same compound.

Is methyl naphthalene-2-sulfonate the polymeric sodium dispersant discussed under a similar name?
No. This compound is a neutral small-molecule ester and does not contain the polymeric framework or sodium counterions of a naphthalene sulfonate-formaldehyde condensate.

What are the best-supported applications of methyl naphthalene-2-sulfonate?
The clearest evidence concerns model nucleophilic substitution, micellar kinetics, hydrolysis, anion competition and selected methylation chemistry.

Does methyl naphthalene-2-sulfonate form the micelles used in those studies?
The published experiments use separate surfactants to create micellar media; MeONs is the reacting substrate and should not automatically be described as a commercial surfactant.

How can methyl naphthalene-2-sulfonate methylate an amine?
A suitable amine can attack the methyl group and displace naphthalene-2-sulfonate, with a tertiary amine potentially forming a quaternary ammonium salt under appropriate conditions.

Is methyl naphthalene-2-sulfonate soluble in every organic solvent?
No universal solubility claim is supported; documented use in particular solvents does not establish saturation values or compatibility with every solvent system.

What is the melting point of methyl naphthalene-2-sulfonate?
A sufficiently corroborated numerical value was not verified for this profile, so no value has been assigned from potentially confused acid, salt or isomer records.

Can an aqueous stock be assumed stable indefinitely?
No. Hydrolysis and reactions with nucleophiles are documented, so stock-solution suitability needs a defined composition, storage history and relevant stability assessment.

Is there a universal purity specification?
No. Assay, moisture and critical impurity limits must be defined for the offered grade and intended application, with the analytical method stated.

Does use in pharmaceutical research make it a medicine?
No. A reagent's role in preparing or studying another compound does not establish therapeutic efficacy or approval of the reagent itself.

What information should accompany an enquiry about methyl naphthalene-2-sulfonate?
Provide the exact name and CAS number, intended reaction or study, quantity, required identity and assay methods, critical impurity limits and documentation needs.

TECHNICAL SUMMARY

Methyl naphthalene-2-sulfonate is a defined aromatic sulfonate ester associated with CAS 5138-53-4. Its formula is C11H10O3S and its average molar mass is approximately 222.26 g/mol. The structural connectivity is naphthyl-S(=O)2-O-CH3, with the sulfonyl group at the 2-position of the aromatic framework. The methyl group is attached through oxygen rather than directly to the ring. This distinction is essential when comparing the ester with ring-methylated sulfonic acids, sodium salts and polymeric formaldehyde condensates.
The abbreviation MeONs appears in research on nucleophilic substitution and organized aqueous reaction media. In the documented methyl-transfer chemistry, a nucleophile attacks the methyl carbon and the naphthalene-2-sulfonate group departs. Methyl naphthalene-2-sulfonate can therefore be used to study the relationship between molecular environment and substitution behavior. It is a reacting substrate rather than a catalyst, and its use in surfactant solutions does not make it a commercial micelle-forming auxiliary.

Micellar kinetics provide the strongest documented application area. Researchers have examined the reactions of methyl naphthalene-2-sulfonate with halides and other nucleophiles in cationic, zwitterionic and mixed micelles. These studies can help distinguish local reactant concentration from changes in the chemical reaction step. Anion competition, surfactant headgroup structure and aggregate composition influence the observed response. Studies with dimeric surfactants further show why changes in aggregate morphology may need to be considered alongside changes in concentration.
Hydrolysis and comparisons with ring-substituted derivatives provide additional mechanistic applications. A related derivative can alter hydrophobic interactions while preserving a similar reaction center, allowing the parent ester to serve as a comparative substrate. Selected synthetic literature also documents methylation of a tertiary amino ester to produce a quaternary ammonium naphthalene-2-sulfonate. This supports a preparative methyl-transfer role without establishing a universal procedure, preferred reagent status or therapeutic application for MeONs itself.

Physical characterization of methyl naphthalene-2-sulfonate should remain tied to the exact identity. A synthetic example reports a white solid and proton NMR signals consistent with an O-methyl group and seven aromatic hydrogens. The calculated neutral monoisotopic mass is approximately 222.0351 Da. Reliable numerical values for melting point, boiling point, density and viscosity were not sufficiently verified for this profile. Data from the parent acid, sodium salt, 1-isomer or 2-naphthyl methanesulfonate must not be substituted to fill these gaps.
For quantitative work, the addition basis should be expressed as a molar amount of the specified ester, with assay correction where justified. Substitution of another naphthalene sulfonate by name similarity would change both identity and interpretation. The intended study should determine which characteristics are critical, rather than relying on a broad catalogue category as evidence of equivalent performance.

Qualification of methyl naphthalene-2-sulfonate should combine identity confirmation with an assay and impurity profile appropriate to the intended experiment or synthesis. Chromatographic area percentage is not automatically a mass assay, and a matching elemental formula does not distinguish constitutional isomers. Stock solutions require separate consideration because the medium can affect reactivity. Controlled handling, dust prevention and appropriate protection are warranted, while specific hazard and transport classifications must follow current product documentation. An enquiry to Ataman Chemicals should identify the exact compound, intended use, required analytical criteria and supply needs so that the offered material can be evaluated against the actual technical requirement.

CONTACT AND TECHNICAL ENQUIRIES

For Methyl naphthalene-2-sulfonate enquiries, provide the complete chemical identity, intended application, required analytical criteria and quantity. Contact Ataman Chemicals to discuss the proposed product and the documentation needed for evaluation.
Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com