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p-Toluenesulfonyl chloride is a reactive aromatic sulfonyl chloride commonly known as tosyl chloride or TsCl.
p-Toluenesulfonyl chloride is a colorless to yellow hygroscopic crystalline solid that reacts with alcohols, amines, water, and other nucleophilic substances.
p-Toluenesulfonyl chloride is widely used in organic synthesis for preparing tosylate esters, sulfonamides, pharmaceutical intermediates, pesticide intermediates, dyes, pigments, resins, coatings, and photosensitive materials.
CAS Number: 98-59-9
EC Number: 202-684-8
Molecular Formula: C₇H₇ClO₂S
Molecular Weight: 190.65 g/mol
SYNONYMS
Tosyl Chloride, TsCl, TOS-Cl, p-Tosyl Chloride, para-Tosyl Chloride, 4-Tosyl Chloride, Tosylchloride, Tosyl Chlorid, p-Toluenesulphonyl Chloride, 4-Toluenesulfonyl Chloride, Toluene-4-sulfonyl Chloride, Toluene-p-sulfonyl Chloride, Toluene para-Sulfonyl Chloride, p-Toluenesulfochloride, para-Toluenesulfochloride, p-Toluenesulfonic Acid Chloride, 4-Methylbenzenesulfonyl Chloride, p-Methylbenzenesulfonyl Chloride, para-Methylbenzenesulfonyl Chloride, 4-Methylbenzene-1-sulfonyl Chloride, p-Methylphenylsulfonyl Chloride, 4-Methylphenylsulfonyl Chloride, p-Tolylsulfonyl Chloride, 4-Tolylsulfonyl Chloride, para-Tolylsulfonyl Chloride, p-Toluenesulfonic Chloride, Toluene-p-sulfochloride, 4-Toluensulfonyl Chloride, Toluene-4-sulphonyl Chloride, para-Toluenesulphonyl Chloride, p-Toluolsulfochlorid, p-Toluolsulfonylchlorid, Chlorure de p-Toluènesulfonyle, Cloruro de p-Toluensulfonilo, Cloruro de Tosilo, Tosil Cloruro, Tosylating Agent, Tosylation Reagent, Alcohol-Activation Reagent, Hydroxyl-Protecting Reagent, Amine-Protecting Reagent, Sulfonamide-Forming Reagent, Sulfonylating Reagent, Aromatic Sulfonyl Chloride, Arylsulfonyl Chloride, Fine-Chemical Intermediate, Pharmaceutical Intermediate, Pesticide Intermediate, Dye Intermediate, Pigment Intermediate, Photosensitive-Material Intermediate, Resin Intermediate, Coating Intermediate, Technical-Grade p-Toluenesulfonyl Chloride, Reagent-Grade p-Toluenesulfonyl Chloride, Synthesis-Grade p-Toluenesulfonyl Chloride, High-Purity p-Toluenesulfonyl Chloride, Crystalline p-Toluenesulfonyl Chloride, CAS 98-59-9, EC 202-684-8, C₇H₇ClO₂S, CH₃C₆H₄SO₂Cl, PubChem CID 7397, NSC 175822, YYROPELSRYBVMQ-UHFFFAOYSA-N
APPLICATIONS
p-Toluenesulfonyl chloride serves as a standard tosylating reagent for converting primary and secondary alcohols into corresponding p-toluenesulfonate esters.
p-Toluenesulfonyl chloride reacts with an alcohol in the presence of a suitable base or acid-accepting system to replace the hydroxyl proton with a tosyl group.
p-Toluenesulfonyl chloride produces tosylate derivatives that retain the original carbon–oxygen bond while converting the hydroxyl group into an effective leaving group.
p-Toluenesulfonyl chloride supports preparation of reactive intermediates used throughout multistep organic synthesis.
p-Toluenesulfonyl chloride functions as an alcohol-activation reagent before nucleophilic substitution reactions.
p-Toluenesulfonyl chloride enables activated tosylates to react with halides, azides, cyanides, thiolates, alkoxides, amines, and other suitable nucleophiles.
p-Toluenesulfonyl chloride supports conversion of hydroxyl-containing molecules into alkyl halides, nitriles, azides, ethers, thioethers, and nitrogen-containing derivatives.
p-Toluenesulfonyl chloride provides an indirect substitution route when direct displacement of an unactivated hydroxyl group would be inefficient.
p-Toluenesulfonyl chloride finds application in selective modification of polyols, glycols, carbohydrates, nucleosides, and other molecules containing several hydroxyl groups.
p-Toluenesulfonyl chloride can preferentially react with a less hindered or catalyst-coordinated hydroxyl group under appropriately selected reaction conditions.
p-Toluenesulfonyl chloride supports regioselective preparation of monotosylated intermediates while leaving other hydroxyl groups available for subsequent transformations.
p-Toluenesulfonyl chloride enables complex molecules to be functionalized stepwise through control of catalyst, base, solvent, temperature, and reagent equivalents.
p-Toluenesulfonyl chloride serves as a reagent for preparing allylic, propargylic, benzylic, and saturated alkyl tosylates.
p-Toluenesulfonyl chloride supports activation of alcohols containing carbon–carbon double bonds without necessarily modifying the unsaturated group.
p-Toluenesulfonyl chloride facilitates production of intermediates used in cyclization, rearrangement, elimination, and carbon–carbon bond-forming reactions.
p-Toluenesulfonyl chloride requires reaction conditions that minimize competing elimination, hydrolysis, oxidation, and isomerization.
p-Toluenesulfonyl chloride functions as an amine-protecting reagent through formation of N-tosyl sulfonamides.
p-Toluenesulfonyl chloride reacts with primary and secondary amines in the presence of a suitable base to produce stable nitrogen–sulfur bonds.
p-Toluenesulfonyl chloride reduces the nucleophilicity and basicity of protected nitrogen atoms during subsequent synthetic operations.
p-Toluenesulfonyl chloride provides the tosyl group, which remains one of the most widely recognized sulfonyl protecting groups in contemporary organic synthesis.
p-Toluenesulfonyl chloride serves as a sulfonamide-forming reagent in medicinal and pharmaceutical chemistry.
p-Toluenesulfonyl chloride reacts with aliphatic amines, aromatic amines, heterocyclic amines, amino alcohols, hydrazines, and related nitrogen nucleophiles.
p-Toluenesulfonyl chloride supports preparation of sulfonamide-containing screening compounds, intermediates, reference materials, and research molecules.
p-Toluenesulfonyl chloride enables rapid construction of structurally diverse sulfonamides through classical sulfonyl chloride–amine coupling.
p-Toluenesulfonyl chloride finds application in pharmaceutical manufacturing as a reagent for temporary functional-group protection and controlled intermediate activation.
p-Toluenesulfonyl chloride enables hydroxyl groups to be converted into tosylates before substitution with nitrogen-, sulfur-, oxygen-, or carbon-based nucleophiles.
p-Toluenesulfonyl chloride supports stereochemically controlled process routes because substitution of a tosylate can proceed with predictable inversion or retention depending on the mechanism.
p-Toluenesulfonyl chloride requires pharmaceutical processes to control residual reagent, p-toluenesulfonic acid, positional isomers, inorganic salts, and solvent residues.
p-Toluenesulfonyl chloride serves in the preparation of hydroxymethylphosphonate tosylates used as intermediates in antiviral-drug synthesis.
p-Toluenesulfonyl chloride converts hydroxymethylphosphonate groups into activated p-toluenesulfonyloxymethyl derivatives.
p-Toluenesulfonyl chloride supports downstream substitution steps used in routes to phosphonate-based antiviral active ingredients.
p-Toluenesulfonyl chloride enables efficient intermediate activation when reagent ratio, base addition, temperature, and water content are carefully controlled.
p-Toluenesulfonyl chloride functions as an intermediate for producing p-toluenesulfonylurea and substituted sulfonylurea compounds.
p-Toluenesulfonyl chloride reacts with ammonia, urea derivatives, amines, and related nitrogen compounds through controlled acyl-substitution chemistry.
p-Toluenesulfonyl chloride supports preparation of sulfonylurea intermediates associated with pharmaceutical and agricultural research.
p-Toluenesulfonyl chloride requires derivative-specific assessment because biological properties cannot be inferred from the parent sulfonyl chloride alone.
p-Toluenesulfonyl chloride serves as an intermediate in the synthesis of selected antibacterial, anti-inflammatory, corticosteroid, and other pharmaceutical compounds.
p-Toluenesulfonyl chloride provides a reactive sulfonyl group for protection, activation, leaving-group formation, and construction of sulfonamide derivatives.
p-Toluenesulfonyl chloride supports routes associated with compounds such as chloramphenicol-related derivatives, thiamphenicol-related materials, and corticosteroid intermediates.
p-Toluenesulfonyl chloride must be introduced only through validated pharmaceutical processes with full impurity and residual-reagent control.
p-Toluenesulfonyl chloride finds application in the preparation of pesticide and plant-protection intermediates.
p-Toluenesulfonyl chloride provides sulfonyl functionality used in selected herbicide, fungicide, and insecticide manufacturing routes.
p-Toluenesulfonyl chloride supports preparation of sulfonylurea-related and other sulfur-containing agricultural intermediates.
p-Toluenesulfonyl chloride requires current regulatory review because use as a manufacturing intermediate does not make it an approved pesticidal active ingredient.
p-Toluenesulfonyl chloride functions as a raw material in dye and organic-pigment intermediate production.
p-Toluenesulfonyl chloride reacts with amino, hydroxy, and other nucleophilic colorant intermediates to form sulfonamide or sulfonate derivatives.
p-Toluenesulfonyl chloride can modify solubility, reactivity, thermal behavior, and compatibility of downstream aromatic intermediates.
p-Toluenesulfonyl chloride supports preparation of intermediates associated with disperse dyes, coupling components, pigments, and specialty colorants.
p-Toluenesulfonyl chloride serves as an intermediate for producing p-toluenesulfonamide.
p-Toluenesulfonyl chloride reacts with ammonia to replace the chloride group with an amino group.
p-Toluenesulfonyl chloride supports manufacture of p-toluenesulfonamide used in plasticizer, resin, coating, and specialty chemical applications.
p-Toluenesulfonyl chloride requires controlled neutralization and washing because hydrogen chloride or chloride salts form during amidation.
p-Toluenesulfonyl chloride functions as a precursor for sodium p-toluenesulfonchloramide and related chloramine compounds.
p-Toluenesulfonyl chloride is first converted into a sulfonamide framework that can subsequently undergo chlorination and salt formation.
p-Toluenesulfonyl chloride supports production routes for oxidizing, disinfecting, analytical, and specialty chloramine reagents.
p-Toluenesulfonyl chloride-derived chloramine products require separate identity, purity, hazard, and regulatory evaluation.
p-Toluenesulfonyl chloride finds application in resin, coating, polymer, and plasticizer intermediate synthesis.
p-Toluenesulfonyl chloride provides a reactive sulfonyl chloride group capable of coupling with hydroxy- or amino-functional monomers and oligomers.
p-Toluenesulfonyl chloride supports modification of polarity, glass-transition behavior, adhesion, flexibility, thermal response, and chemical resistance in suitable derivatives.
p-Toluenesulfonyl chloride is identified in process literature as an intermediate associated with resins, coatings, plasticizers, and photosensitive materials.
p-Toluenesulfonyl chloride serves as a functionalization reagent in polymer and materials research.
p-Toluenesulfonyl chloride converts hydroxyl- or amino-functional polymers into tosylated or sulfonamide-containing materials.
p-Toluenesulfonyl chloride enables introduction of leaving groups for subsequent grafting, substitution, crosslinking, or surface modification.
p-Toluenesulfonyl chloride requires polymer-specific testing because excessive tosylation can cause chain degradation, insolubility, crosslinking, or loss of mechanical performance.
p-Toluenesulfonyl chloride functions as a reagent in preparation of photosensitive and imaging-related organic materials.
p-Toluenesulfonyl chloride supports derivatization of hydroxy- and amino-containing aromatic compounds used in light-sensitive or photoactive systems.
p-Toluenesulfonyl chloride can introduce sulfonyl groups that alter solubility, crystallinity, film formation, and development behavior.
p-Toluenesulfonyl chloride requires each derived photosensitive compound to be evaluated independently for optical response and process performance.
p-Toluenesulfonyl chloride serves as a reagent for activating carboxylic acids in selected peptide and amide synthesis methods.
p-Toluenesulfonyl chloride can form reactive mixed intermediates that promote coupling between carboxyl and amino groups.
p-Toluenesulfonyl chloride supports historical and specialized peptide-bond-forming procedures under controlled reaction conditions.
p-Toluenesulfonyl chloride requires careful suppression of racemization, overactivation, side reactions, and sulfonylation of unintended nucleophiles.
p-Toluenesulfonyl chloride functions as a dehydrating or activating reagent in selected amide, urea, carbodiimide, nitrile, and heterocycle syntheses.
p-Toluenesulfonyl chloride can activate oxygen-containing functional groups before elimination of water or another leaving group.
p-Toluenesulfonyl chloride supports conversion of suitable ureas into carbodiimides and selected amides into dehydrated products.
p-Toluenesulfonyl chloride requires reaction-specific control because acidic chloride-containing by-products and excess reagent can modify sensitive substrates.
p-Toluenesulfonyl chloride finds application as a sulfur-containing reagent in modern catalytic and radical organic reactions.
p-Toluenesulfonyl chloride can participate in transformations involving cleavage or transfer of sulfonyl, chlorine, or arylsulfonyl functionality.
p-Toluenesulfonyl chloride has been investigated as a chlorine source in site-selective carbon–hydrogen chlorination of aromatic and heteroaromatic compounds.
p-Toluenesulfonyl chloride enables specialized synthetic pathways that require dedicated catalyst, oxidant, solvent, and reaction-hazard evaluation.
p-Toluenesulfonyl chloride serves as a starting material for preparing sulfones, sulfinates, sulfonates, sulfonamides, and sulfur-containing heterocyclic intermediates.
p-Toluenesulfonyl chloride undergoes substitution at sulfur with oxygen-, nitrogen-, sulfur-, and carbon-centered nucleophiles.
p-Toluenesulfonyl chloride provides the p-tolylsulfonyl fragment as a recognizable protecting, activating, and structural group.
p-Toluenesulfonyl chloride supports synthetic route development across fine-chemical, medicinal, agricultural, and materials chemistry.
p-Toluenesulfonyl chloride functions as a derivatization reagent in analytical chemistry.
p-Toluenesulfonyl chloride reacts with alcohols, phenols, amines, and other nucleophilic analytes to form derivatives having altered volatility, stability, retention, or detectability.
p-Toluenesulfonyl chloride supports chromatographic separation of compounds that are otherwise highly polar, unstable, or weakly detectable.
p-Toluenesulfonyl chloride requires derivatization blanks and controlled reagent purity because hydrolysis products and residual reagent can create interfering peaks.
p-Toluenesulfonyl chloride finds application as an identification reagent for alcohols, phenols, amines, and polyfunctional organic compounds.
p-Toluenesulfonyl chloride converts suitable analytes into crystalline tosylates or sulfonamides that may possess characteristic melting behavior.
p-Toluenesulfonyl chloride supports structural confirmation when derivative formation is combined with spectroscopy, chromatography, and elemental analysis.
p-Toluenesulfonyl chloride-derived melting points should not be used alone because impurities, polymorphism, and positional isomers can affect the result.
p-Toluenesulfonyl chloride serves as an analytical reference and system-suitability substance in quality-control laboratories.
p-Toluenesulfonyl chloride supports verification of gas-chromatographic, liquid-chromatographic, infrared, mass-spectrometric, and moisture-sensitive analytical methods.
p-Toluenesulfonyl chloride provides established molecular identity and spectroscopic reference information.
p-Toluenesulfonyl chloride requires storage under dry conditions because hydrolysis changes assay, chromatographic purity, acidity, and melting behavior.
p-Toluenesulfonyl chloride functions as a process-development reference for studying sulfonyl chloride reactivity.
p-Toluenesulfonyl chloride enables comparison of bases, catalysts, solvents, temperatures, and reagent-addition strategies in sulfonylation reactions.
p-Toluenesulfonyl chloride supports evaluation of reaction calorimetry, hydrogen chloride evolution, mixing, crystallization, and impurity formation.
p-Toluenesulfonyl chloride provides useful scale-up information only when water exclusion, heat removal, ventilation, and containment are representative of commercial processing.
p-Toluenesulfonyl chloride serves as an educational reagent in advanced organic chemistry laboratories.
p-Toluenesulfonyl chloride demonstrates nucleophilic substitution at a sulfonyl sulfur atom and conversion of hydroxyl groups into leaving groups.
p-Toluenesulfonyl chloride supports instruction in protecting-group chemistry, sulfonamide formation, recrystallization, infrared spectroscopy, and reaction workup.
p-Toluenesulfonyl chloride requires professional supervision, dry equipment, effective ventilation, eye protection, and controlled neutralization of acidic residues.
DESCRIPTION
p-Toluenesulfonyl chloride is the common name of the compound systematically identified as 4-methylbenzenesulfonyl chloride.
p-Toluenesulfonyl chloride is identified by CAS Number 98-59-9 and EC Number 202-684-8.
p-Toluenesulfonyl chloride has the molecular formula C₇H₇ClO₂S.
p-Toluenesulfonyl chloride has a molecular weight of approximately 190.65 g/mol.
p-Toluenesulfonyl chloride contains a benzene ring substituted with a methyl group and a sulfonyl chloride group in para positions.
The sulfonyl chloride group consists of sulfur bonded to two oxygen atoms, one chlorine atom, and the aromatic ring.
The sulfur center is strongly electrophilic and undergoes nucleophilic substitution with alcohols, amines, water, and other nucleophiles.
The para-methyl group contributes hydrophobicity and provides the recognizable p-tolylsulfonyl or tosyl structural unit.
p-Toluenesulfonyl chloride normally appears as colorless to yellow hygroscopic crystals.
p-Toluenesulfonyl chloride possesses a pungent odor associated partly with the reactive material and acidic hydrolysis products.
p-Toluenesulfonyl chloride may become discolored, damp, lumpy, or partially liquefied after exposure to humid air.
p-Toluenesulfonyl chloride commercial appearance depends on purity, positional-isomer content, moisture, particle size, and storage history.
p-Toluenesulfonyl chloride has a melting range of approximately 69–71°C.
p-Toluenesulfonyl chloride can therefore soften or melt during warm storage, heated processing, or summer transportation conditions.
p-Toluenesulfonyl chloride recrystallizes when cooled below its grade-dependent solidification range.
p-Toluenesulfonyl chloride thermal conditioning should be gradual and should avoid localized overheating.
p-Toluenesulfonyl chloride has a reported reduced-pressure boiling point near 145°C at approximately 2.0 kPa.
p-Toluenesulfonyl chloride decomposes when strongly heated and should not be handled as a thermally inert distillable compound.
p-Toluenesulfonyl chloride thermal decomposition generates toxic and corrosive fumes including sulfur oxides and hydrogen chloride.
p-Toluenesulfonyl chloride high-temperature purification requires corrosion-resistant closed equipment and effective off-gas treatment.
p-Toluenesulfonyl chloride has a representative density of approximately 1.3 g/cm³.
p-Toluenesulfonyl chloride has a vapor pressure of approximately 0.16 Pa at 25°C.
p-Toluenesulfonyl chloride therefore has low volatility as an undisturbed solid at ordinary room temperature.
p-Toluenesulfonyl chloride can nevertheless generate airborne dust rapidly during pouring, grinding, sieving, conveying, and packaging.
p-Toluenesulfonyl chloride has a reported relative vapor density of approximately 6.6 compared with air.
Vapors or decomposition fumes from heated p-Toluenesulfonyl chloride may therefore accumulate in poorly ventilated low areas.
Dust and acidic fumes can spread beyond the immediate handling point when local exhaust is inadequate.
Ventilation should control both particulate exposure and hydrogen chloride released through hydrolysis.
p-Toluenesulfonyl chloride does not simply dissolve in water.
p-Toluenesulfonyl chloride reacts with water and moist air to produce p-toluenesulfonic acid and hydrogen chloride.
p-Toluenesulfonyl chloride hydrolysis can generate heat, corrosive acidity, fumes, and loss of active reagent.
p-Toluenesulfonyl chloride must consequently be stored and processed under dry conditions.
p-Toluenesulfonyl chloride reacts with alcohols to form p-toluenesulfonate esters.
p-Toluenesulfonyl chloride reacts with amines to form p-toluenesulfonamides.
p-Toluenesulfonyl chloride reacts with ammonia to form p-toluenesulfonamide.
p-Toluenesulfonyl chloride reacts with hydroxide or water to form p-toluenesulfonate or p-toluenesulfonic acid.
p-Toluenesulfonyl chloride sulfonylation reactions release hydrogen chloride or generate chloride salts when a base is present.
Suitable bases neutralize the acidic by-product and promote nucleophilic attack at sulfur.
p-Toluenesulfonyl chloride has a reported log octanol–water partition coefficient of approximately 3.49.
The parent compound therefore shows appreciable affinity for organic phases before it reacts or hydrolyzes.
p-Toluenesulfonyl chloride environmental behavior is strongly affected by hydrolysis and reaction with nucleophilic materials.
Concentrated p-Toluenesulfonyl chloride and contaminated reaction residues should not be released to water or soil.
p-Toluenesulfonyl chloride has a closed-cup flash point of approximately 128°C.
p-Toluenesulfonyl chloride has a reported autoignition temperature near 492°C.
p-Toluenesulfonyl chloride is classified as combustible and can release irritating or toxic gases during fire.
p-Toluenesulfonyl chloride fire control should use dry powder or carbon dioxide rather than water or foam.
Water and foam are unsuitable for a p-Toluenesulfonyl chloride fire because the substance reacts with water.
Application of water can increase hydrolysis, corrosive hydrogen chloride generation, spattering, and contaminated runoff.
Containers exposed to fire may melt, leak, or release sulfur- and chlorine-containing decomposition products.
Firefighters require full protective equipment and independent respiratory protection.
p-Toluenesulfonyl chloride is manufactured industrially through chlorosulfonation of toluene or through conversion of p-toluenesulfonic acid and related salts into the sulfonyl chloride.
Chlorosulfonic acid can provide both sulfonation and chlorination functionality in suitable production routes.
Alternative processes use chlorinating reagents to convert p-toluenesulfonic acid, p-toluenesulfonate salts, or p-toluenesulfonamide derivatives.
Industrial route selection affects waste-acid generation, positional-isomer formation, corrosion, purification demand, and product quality.
Direct chlorosulfonation of toluene can generate both ortho- and para-toluenesulfonyl chloride-related products.
The para isomer crystallizes more readily than the lower-melting ortho-rich fraction under selected cooling conditions.
Crystallization, filtration, centrifugation, washing, vacuum distillation, and recrystallization can be used during separation and purification.
Positional-isomer control is important because ortho contamination changes melting point, appearance, assay, and synthetic performance.
p-Toluenesulfonyl chloride production can be operated through batch reactors or continuous microchannel equipment.
Continuous systems can improve heat transfer, reagent mixing, residence-time control, and containment of strongly acidic reactants.
Crystallization and solids handling remain important because the purified para product is normally isolated as a solid.
Production equipment must resist chlorosulfonic acid, hydrogen chloride, sulfuric acid, and sulfonyl chloride reaction mixtures.
p-Toluenesulfonyl chloride quality control commonly includes appearance, assay, melting range, moisture, acidity, p-toluenesulfonic acid, and positional-isomer content.
Chromatographic testing can measure p-Toluenesulfonyl chloride, o-toluenesulfonyl chloride, hydrolysis products, and organic impurities.
Water determination is particularly important because small amounts of moisture consume active sulfonyl chloride.
Reagent-grade and pharmaceutical-process grades may require tighter impurity limits than general technical material.
p-Toluenesulfonyl chloride should have a sharp melting range when highly pure and dry.
A depressed or broadened melting range can indicate ortho-isomer contamination, moisture, hydrolysis, solvent residue, or other impurities.
Increasing acidity during storage can indicate conversion to p-toluenesulfonic acid.
Representative sampling requires protection of the sample from atmospheric humidity.
p-Toluenesulfonyl chloride causes skin irritation.
p-Toluenesulfonyl chloride causes serious eye irritation.
p-Toluenesulfonyl chloride irritates the respiratory tract after inhalation of dust or acidic fumes.
p-Toluenesulfonyl chloride can reach harmful airborne particle concentrations quickly when finely divided material is dispersed.
p-Toluenesulfonyl chloride short-term inhalation exposure may cause coughing and respiratory discomfort.
p-Toluenesulfonyl chloride skin contact may cause redness and pain.
p-Toluenesulfonyl chloride eye contact may cause severe irritation, redness, pain, and risk of tissue injury.
p-Toluenesulfonyl chloride ingestion may cause sore throat, irritation, and gastrointestinal injury.
p-Toluenesulfonyl chloride is harmful to aquatic organisms.
p-Toluenesulfonyl chloride should not be discharged into drains, sewers, soil, groundwater, or surface water.
Hydrolysis does not eliminate environmental concern because acidic and organic transformation products remain.
Spill response should recover dry material without dispersing dust or using uncontrolled water washing.
p-Toluenesulfonyl chloride is associated with UN Hazard Class 8 and Packing Group II in the cited international transport guidance.
The exact shipping name and UN Number should be confirmed from current jurisdiction-specific transport documentation.
Transport packaging should be moisture resistant, tightly closed, corrosion resistant, and protected against breakage.
Damaged packages can release irritating dust and corrosive hydrogen chloride after contact with atmospheric moisture.
PROPERTIES
Chemical Name: p-Toluenesulfonyl chloride
Common Name: Tosyl chloride
Abbreviation: TsCl
Systematic Name: 4-Methylbenzenesulfonyl chloride
Alternative Systematic Name: Toluene-4-sulfonyl chloride
CAS Number: 98-59-9
EC Number: 202-684-8
PubChem CID: 7397
Molecular Formula: C₇H₇ClO₂S
Condensed Structural Formula: CH₃C₆H₄SO₂Cl
Molecular Weight: 190.65 g/mol
Exact Molecular Weight: Approximately 189.9855 Da
InChIKey: YYROPELSRYBVMQ-UHFFFAOYSA-N
Chemical Family: Aromatic sulfonyl chlorides
Chemical Classification: Arylsulfonyl chloride
Functional Group: Sulfonyl chloride
Aromatic Substitution Pattern: Para or 1,4-substitution
Physical State: Crystalline solid
Appearance: Colorless to yellow hygroscopic crystals
Odor: Pungent
Melting Point: Approximately 69–71°C
Reduced-Pressure Boiling Point: Approximately 145°C at 2.0 kPa
Density: Approximately 1.3 g/cm³
Water Solubility: Reacts with water
Water-Reaction Products: p-Toluenesulfonic acid and hydrogen chloride
Vapor Pressure at 25°C: Approximately 0.16 Pa
Relative Vapor Density: Approximately 6.6
Log Pow: Approximately 3.49
Flash Point: Approximately 128°C
Flash-Point Method: Closed cup
Autoignition Temperature: Approximately 492°C
Volatility: Low as an undisturbed solid
Dust Formation: Possible during dry handling
Hygroscopicity: Hygroscopic
Combustibility: Combustible
Primary Chemical Function: Sulfonylating reagent
Primary Synthetic Function: Conversion of alcohols into tosylate esters
Additional Synthetic Function: Conversion of amines into sulfonamides
Protecting-Group Function: Tosyl protection of amines and selected hydroxyl groups
Activation Function: Conversion of hydroxyl groups into effective leaving groups
Intermediate Applications: Pharmaceuticals, pesticides, dyes, pigments, resins, coatings, plasticizers, and photosensitive materials
Common Reaction By-Product: Hydrogen chloride or chloride salts
Primary Hydrolysis Product: p-Toluenesulfonic acid
Ammonia-Reaction Product: p-Toluenesulfonamide
Alcohol-Reaction Product: Alkyl or aryl p-toluenesulfonate
Amine-Reaction Product: N-Substituted p-toluenesulfonamide
Skin Hazard: Causes irritation
Eye Hazard: Causes serious irritation
Respiratory Hazard: Irritating to the respiratory tract
Aquatic Hazard: Harmful to aquatic organisms
UN Hazard Class: 8
UN Packing Group: II
Chemical Stability: Stable when kept dry, cool, and tightly closed
Moisture Stability: Unstable to water and humid air
Thermal Stability: Decomposes on strong heating
Incompatible Materials: Water, humid air, strong bases, strong nucleophiles, strong oxidizing agents, and other reactive materials identified in the current Safety Data Sheet
Hazardous Decomposition Products: Hydrogen chloride, sulfur oxides, carbon oxides, smoke, and other irritating or toxic fumes
Suitable Fire-Extinguishing Media: Dry powder and carbon dioxide
Unsuitable Fire-Extinguishing Media: Water and foam
Recommended Storage: Dry, cool, tightly closed, and well-ventilated storage
Drain Precaution: Store in an area without direct drain or sewer access
Quality-Control Parameters: Appearance, assay, melting range, moisture, acidity, hydrolysis products, and positional-isomer content
Current Data Requirement: Confirm purity, physical form, transport classification, hazard classification, occupational controls, and shelf life from the current grade-specific documentation.
FIRST AID
Inhalation:
Move the affected person immediately to fresh air.
Keep the person at rest in a position comfortable for breathing.
Avoid further exposure to p-Toluenesulfonyl chloride dust, hydrogen chloride, smoke, or thermal-decomposition fumes.
Obtain prompt medical attention if coughing, sore throat, chest discomfort, wheezing, breathing difficulty, or other symptoms develop.
Provide oxygen or assisted breathing only through trained personnel using suitable protective equipment.
Skin Contact:
Remove contaminated clothing, footwear, and accessories immediately.
Brush away loose dry material carefully without dispersing dust.
Rinse the affected skin with plenty of water or use an emergency shower.
Wash the skin thoroughly with soap and water.
Obtain medical attention if redness, pain, blistering, irritation, or signs of a chemical burn develop.
Wash contaminated clothing separately before reuse.
Eye Contact:
Rinse the eyes immediately with plenty of clean, gently flowing water.
Hold the eyelids open to ensure complete irrigation.
Remove contact lenses when present and easy to do, then continue rinsing.
Continue rinsing for at least 15 minutes.
Obtain immediate medical attention because p-Toluenesulfonyl chloride causes serious eye irritation and may produce corrosive hydrolysis products.
Continue irrigation during transport when advised by medical personnel.
Ingestion:
Rinse the mouth thoroughly with water.
Do not induce vomiting unless directed by qualified medical personnel or a poison center.
Never give anything by mouth to an unconscious or convulsing person.
Give small quantities of water only when the person is conscious and medical guidance permits.
Obtain immediate medical attention because p-Toluenesulfonyl chloride and its hydrolysis products can irritate or damage the mouth, throat, and gastrointestinal tract.
Provide the current Safety Data Sheet and product label to medical personnel.
Note to Physicians:
No substance-specific antidote should be assumed.
Provide supportive care and treat according to the patient’s symptoms and clinical condition.
Assess the eyes, skin, upper respiratory tract, lungs, mouth, esophagus, and gastrointestinal tract after significant exposure.
Consider delayed pulmonary irritation following inhalation of dust, hydrogen chloride, or fire-decomposition fumes.
Treat exposure as involving a moisture-reactive sulfonyl chloride capable of generating hydrochloric and sulfonic acids.
Use current poison-center guidance and the grade-specific Safety Data Sheet as the primary medical references.
HANDLING AND STORAGE
Handling:
Handle p-Toluenesulfonyl chloride in accordance with strict industrial-hygiene and moisture-sensitive chemical-handling procedures.
Review the current technical specification and Safety Data Sheet before opening, sampling, transferring, or processing the material.
Avoid all unnecessary contact with the skin, eyes, and clothing.
Do not breathe dust, hydrogen chloride, aerosol, smoke, or thermal-decomposition fumes.
Use enclosed charging, weighing, reaction, filtration, transfer, and packaging systems wherever reasonably practicable.
Open containers only in a dry and effectively ventilated handling area.
Prevent contact with water, humid air, wet equipment, aqueous residues, and damp cleaning materials.
Use clean, completely dry, and chemically compatible equipment for sampling, weighing, transfer, and reaction.
Add p-Toluenesulfonyl chloride gradually to reaction mixtures under controlled temperature and agitation.
Provide sufficient heat-removal capacity for exothermic sulfonylation, hydrolysis, and neutralization reactions.
Control base addition to prevent localized overheating, excessive hydrogen chloride evolution, and uncontrolled foaming.
Wash the hands, face, and exposed skin thoroughly after handling.
Do not eat, drink, or smoke in areas where p-Toluenesulfonyl chloride is processed.
Keep containers tightly closed whenever the material is not being sampled or transferred.
Ventilation:
Provide effective general ventilation in storage and processing areas.
Use local exhaust ventilation at bag-emptying points, weighing stations, reactors, filters, dryers, mills, and packaging equipment.
Capture dust and hydrogen chloride at the source rather than allowing contamination to spread through the workplace.
Use enclosed fume extraction during laboratory-scale weighing and reaction charging.
Provide corrosion-resistant exhaust ducts and gas-treatment equipment where acidic fumes may be generated.
Use dust-collection equipment suitable for combustible and corrosive particulate material.
Prevent recirculation of contaminated air unless it has been adequately filtered and treated.
Use suitable particulate and acid-gas respiratory protection when engineering controls cannot adequately limit exposure.
Use supplied-air or self-contained respiratory equipment for emergency response, major releases, fires, or unknown concentrations.
Select respiratory protection through a documented occupational-exposure and hazard assessment.
Inspect ventilation, scrubbers, filters, and dust collectors regularly for corrosion, blockage, leakage, and loss of extraction efficiency.
Storage:
Store p-Toluenesulfonyl chloride in tightly closed, moisture-resistant, and correctly labeled containers.
Keep the material in a cool, dry, secure, and well-ventilated location.
Store p-Toluenesulfonyl chloride in an area without direct drain or sewer access.
Protect p-Toluenesulfonyl chloride from water, humid air, condensation, rain, steam, and wet firefighting systems.
Keep p-Toluenesulfonyl chloride separated from strong bases, strong nucleophiles, oxidizing agents, alcohols, amines, and incompatible reactive chemicals.
Keep the material away from open flames, hot surfaces, sparks, and uncontrolled heat.
Maintain storage temperatures that prevent unnecessary melting and repeated recrystallization.
Do not use steam coils or direct water-based heating where leakage could contact the product.
Use dry inert-gas blanketing where required by the current grade documentation or process design.
Prevent water, dirt, rust, bases, alcohols, amines, and process residues from entering opened containers.
Carefully reseal partially used containers immediately after sampling or transfer.
Use first-in, first-out stock rotation within the applicable shelf life.
Inspect containers regularly for moisture ingress, corrosion, swelling, leakage, caking, discoloration, acidity, or damaged seals.
Place breakable primary containers inside closed and unbreakable secondary containment.
Spill and Leak Procedures:
Restrict access to the affected area and remove unnecessary personnel.
Evacuate the immediate area when a large release or strong hydrogen chloride odor is present.
Eliminate ignition sources when this can be done safely.
Prevent contact between the spilled material and water, foam, wet absorbents, or damp cleaning tools.
Provide effective local ventilation before beginning recovery operations.
Wear chemical-resistant gloves, protective clothing, eye protection, and respiratory protection suitable for dust and acid gases.
Avoid dry sweeping methods that disperse fine particles into the air.
Carefully collect solid p-Toluenesulfonyl chloride with dry non-sparking tools or a suitable hazardous-dust vacuum.
Place recovered material in dry, tightly closed, chemically compatible, and correctly labeled containers.
Collect contaminated dry absorbent, disposable protective equipment, and cleaning residues separately.
Do not wash the spill directly into drains or use uncontrolled water flushing.
Treat residual contamination through a controlled neutralization or decontamination procedure performed by trained personnel.
Monitor the area for acidic fumes during cleanup because atmospheric moisture can continue to hydrolyze residues.
Prevent p-Toluenesulfonyl chloride from entering drains, sewers, soil, groundwater, or surface water.
Dispose of recovered material and residues through an authorized hazardous-waste route.
Handling Precautions:
Wear chemical-resistant protective gloves selected from documented compatibility and permeation data.
Use tightly fitting chemical goggles.
Wear a face shield in addition to goggles where powder, molten material, or reaction-mixture splashing is reasonably foreseeable.
Use protective clothing and closed chemical-resistant footwear.
Use heat-resistant protective equipment when handling warmed or molten p-Toluenesulfonyl chloride.
Provide accessible eyewash and emergency-shower equipment near major handling locations.
Keep emergency eyewash water physically separated from stored product while maintaining immediate worker access.
Use suitable particulate and acid-gas respiratory protection during operations capable of generating dust or hydrogen chloride.
Ground and bond conductive handling equipment where combustible-dust or electrostatic hazards have been identified.
Inspect containers, seals, valves, charging systems, filters, ventilation ducts, scrubbers, and dust collectors before use.
Confirm that all equipment is dry before contact with p-Toluenesulfonyl chloride.
Do not extinguish a p-Toluenesulfonyl chloride fire with water or foam.
Use dry powder or carbon dioxide in accordance with the current emergency plan.
Do not mix p-Toluenesulfonyl chloride with water, strong bases, strong oxidants, alcohols, amines, or unfamiliar nucleophiles without a documented reaction-hazard assessment.
Review the current technical specification, Safety Data Sheet, certificate of analysis, occupational requirements, transport rules, environmental regulations, and emergency procedures before production, formulation, storage, cleaning, or disposal.
