Chlorinating Agent · Acid Chloride Reagent · UN 1836
Thionyl chloride (SOCl₂) is the workhorse chlorinating agent that turns carboxylic acids into acid chlorides for API, agrochemical and dye synthesis. Sourced by Chelora Pharmachem, Mumbai, and delivered across India with a batch COA and SDS.
How Buying Works
Send the quantity, grade (technical, synthesis or high-purity), packing, delivery city and target date. Quote CAS 7719-09-7 so there is no confusion.
Price, lead time and packing in one reply, with the specification, COA and SDS/MSDS for your QA team to review.
Samples can be arranged for QC checks and trial reactions, in UN-approved dangerous-goods packing, before your commercial order.
Packed, labelled and sent with invoice, batch COA and transport documents. Repeat orders are planned with you.
Product Overview
Thionyl Chloride (thionyl dichloride, sulphinyl chloride; CAS 7719-09-7) is an inorganic sulphur(IV) compound with the formula SOCl2. It is a colourless to pale yellow, fuming liquid with a sharp, choking odour, boiling at about 76 °C. In chemical plants it is valued as a chlorinating agent: it converts carboxylic acids into acid chlorides and alcohols into alkyl chlorides, and its by-products, sulphur dioxide and hydrogen chloride, leave the reaction as gases.
That clean work-up is why thionyl chloride is a standard reagent in API, agrochemical, dye and pigment synthesis, from laboratory flasks to multi-tonne glass-lined reactors. It is also the cathode material and electrolyte solvent in lithium–thionyl chloride primary cells, which power utility meters, tracking devices and emergency beacons. Because it reacts violently with water, releasing HCl and SO2, it must be handled dry, in closed systems with gas scrubbing.
As a chemical supplier in Mumbai, Chelora Pharmachem supplies thionyl chloride to API, intermediate, agrochemical, dye and specialty-chemical manufacturers across India. Every lot is packed in UN-approved containers and shipped as a Class 8 dangerous good by licensed transporters, with a batch-wise COA, SDS/MSDS and specification for your QA, stores and EHS teams. Buyers who make acid chlorides and amides often also source Chloroacetyl Chloride from us for their acylation steps.
In Depth
Thionyl chloride is a small inorganic molecule: one sulphur atom in the +4 oxidation state, bonded to one oxygen and two chlorine atoms. A lone pair on sulphur gives it a trigonal pyramidal shape. It is a dense, volatile liquid that is miscible with dry aprotic solvents such as toluene and chloroform, but it reacts with water, alcohols and amines rather than simply dissolving.
With a carboxylic acid, thionyl chloride gives the acid chloride, sulphur dioxide and hydrogen chloride. A catalytic amount of DMF speeds this up through a Vilsmeier-type intermediate. Alcohols are converted into alkyl chlorides, or into sulphite esters when alcohol is in excess. Because both by-products are gases, excess reagent is simply distilled off and the product needs little purification.
The main industrial route reacts sulphur trioxide with sulphur dichloride, giving thionyl chloride and sulphur dioxide. Other routes chlorinate sulphur dioxide with chlorine and sulphur chlorides, or react it with phosphorus pentachloride. The crude liquid is then purified by distillation, which removes the sulphur chlorides and sulphuryl chloride that buyers most often limit on a specification.
Many APIs are built by joining an acid and an amine or alcohol. Converting the acid into its acid chloride with thionyl chloride makes that amide or ester bond form quickly and cleanly. It is also used to make alkyl chloride intermediates and, with methanol, amino acid methyl ester hydrochlorides. The gaseous by-products are scrubbed, and residual reagent is controlled in the isolated intermediate.
Start with assay, appearance and colour, then compare limits for sulphuryl chloride, sulphur chlorides, iron and non-volatile residue, which can affect colour and side reactions. Confirm the packing suits your unloading system and that drums are UN-approved for Packing Group I. Ask for the COA and SDS of the actual batch, and check your site’s storage licence and scrubber capacity.
Chelora Pharmachem supplies thionyl chloride (CAS 7719-09-7) from its centralized sales office in Mumbai to API, intermediate, agrochemical, dye and battery manufacturers across India. Share the grade, quantity, packing and delivery location, and our team replies with price, lead time, dangerous-goods transport details and documents, from trial lots for process development to regular bulk supply.
Global Sourcing
Our focus is the Indian market. When local supply is short, or you need a specific purity or origin, our international sourcing desk brings thionyl chloride in from trusted producers abroad, and our Mumbai team handles import, dangerous-goods documents and delivery to your plant.
Product Profile
The identifiers and properties purchase and QA teams ask for first. Batch values are always confirmed on the COA.
Identity
EC 231-748-8. Also sold as thionyl dichloride or sulphinyl chloride. UN 1836 for transport.
Sulphur(IV) bonded to one oxygen and two chlorines in a pyramidal molecule.
Appearance
Colourless to pale yellow liquid with a pungent odour; yellows on ageing. Density about 1.64 g/cm³.
Water reactivity
Water and moist air turn it into hydrogen chloride and sulphur dioxide gases. Keep it dry at all times.
Technical Data
Reference data for Thionyl Chloride, useful when writing a specification, checking an SDS or planning storage and transport.
| Property | Value |
|---|---|
| IUPAC name | Thionyl dichloride |
| Synonyms | Thionyl dichloride, sulphinyl chloride (sulfinyl dichloride), sulphurous oxychloride, sulphur chloride oxide |
| CAS number | 7719-09-7 |
| EC number | 231-748-8 |
| PubChem CID | 24386 |
| Molecular formula | SOCl2 |
| Molar mass | 118.97 g/mol |
| Appearance | Colourless to pale yellow, fuming liquid; yellows on ageing |
| Odour | Pungent, choking |
| Melting point | About −104.5 °C |
| Boiling point | About 75–76 °C at 1013 hPa; slowly decomposes when heated above its boiling point |
| Density | About 1.64 g/cm³ at 20 °C |
| Vapour pressure | About 120–130 hPa at 20 °C |
| Solubility in water | Reacts violently, giving hydrogen chloride and sulphur dioxide (SOCl2 + H2O → 2 HCl + SO2) |
| Other solvents | Miscible with dry aprotic solvents such as toluene, chloroform and diethyl ether; reacts with alcohols, amines and other protic solvents |
| HS code | 2812.17 |
| Transport | UN 1836, Thionyl chloride, Class 8 (corrosive), Packing Group I; check the batch SDS |
Literature values for reference. Supplied material is tested batch-wise and reported on the COA.
Applications
Its main job is making acid chlorides and alkyl chlorides for drug, crop-protection and colour chemistry. It is also the active cathode liquid in long-life lithium primary cells.
Converts carboxylic acids into acid chlorides for amide and ester coupling steps, and alcohols into alkyl chloride intermediates. With methanol it gives amino acid methyl ester hydrochlorides, common building blocks in peptide and API synthesis.
Chlorinating reagent
Used to make the acid chlorides behind many crop-protection actives, such as the cyclopropane acid chlorides that are esterified into pyrethroid insecticides like cypermethrin and permethrin, and other chlorinated intermediates for herbicides and fungicides made by Indian agrochemical producers.
Crop-protection chemistry
Acid chlorides made with thionyl chloride are condensed with aromatic amines to build amide-linked azo pigments, anthraquinone dyes and other colour intermediates. Clean, complete conversion helps the final shade, strength and purity, which is why dye and pigment makers specify low-impurity material.
Colour chemistry
In Li–SOCl₂ primary cells, thionyl chloride is both the cathode material and the electrolyte solvent. These cells offer about 3.6 V, high energy density and a very long shelf life, for utility meters, IoT trackers and emergency beacons.
High-purity grade
A versatile laboratory and fine-chemical reagent. It forms the Vilsmeier reagent with DMF, makes sulphite esters and sulphinyl chlorides, and dehydrates metal chloride hydrates to their anhydrous forms. R&D and kilo labs use it in route scouting before scale-up.
Specialty reagent
Quality & Compliance
Every supply is backed by the documents your QA, regulatory and stores teams expect.
COA, batch-wise
Tests, limits and results for the exact batch you receive, shared before dispatch.
SDS / MSDS
Hazards, safe handling, storage, transport and first-aid measures for Thionyl Chloride.
Technical data
Typical properties and the specification we supply against, to match with your in-house spec.
On request
Additional documents for vendor approval and audits can be arranged on request.
Safety & Handling
A short summary for stores, production and EHS teams. It does not replace the Safety Data Sheet supplied with every batch.
Supplier SDSs classify it as harmful if swallowed, toxic if inhaled, causing severe skin burns and eye damage and respiratory irritation. It reacts violently with water and liberates toxic gas. Signal word: Danger. Check the SDS of the batch for the classification that applies.
H302H314H331H335EUH014EUH029
Handle only in closed systems or under efficient local exhaust with a gas scrubber. Wear a face shield over chemical goggles, acid-resistant gloves and clothing, and use a suitable respirator where vapour may escape. Keep an emergency shower and eyewash close by.
Store in tightly closed, corrosion-resistant containers in a cool, dry, well-ventilated and locked store, below about 30 °C. Keep away from water and moist air, alcohols, amines, bases and metals, and never store it where water from sprinklers can reach it.
Regulated as UN 1836, Thionyl chloride, Class 8 (corrosive), Packing Group I for road and sea. Air transport is generally not permitted. It is also a Chemical Weapons Convention Schedule 3 chemical, so imports and exports may need end-use documents.
Evacuate the area and approach upwind with full protection. Never use water on a spill. Contain it with dry sand or another dry, inert absorbent, collect it into closed containers, and keep it out of drains, soil and water courses.
PAN India Delivery
From our centralized sales office in Mumbai, we supply Thionyl Chloride to buyers in every major manufacturing cluster.
MumbaiMumbai, Thane, Navi Mumbai, Tarapur, Boisar, Pune and Aurangabad.
AhmedabadAhmedabad, Vadodara, Ankleshwar and Vapi.
HyderabadHyderabad and Visakhapatnam.
BaddiBaddi and Haridwar.
GoaPharma and chemical units across Goa.
BengaluruBengaluru and Chennai.
IndoreIndore, Pithampur and Sikkim.
Specification
A typical specification for synthesis-grade thionyl chloride (assay ≥ 99%). High-purity material is available on enquiry; share your in-house specification and we quote against it.
The Chemistry
Made
Sulphur trioxide reacts with sulphur dichloride to give thionyl chloride and sulphur dioxide. Other routes start from sulphur dioxide and chlorine. Distillation then removes sulphur chlorides, sulphuryl chloride and other impurities to reach the purity grade the buyer requires.
Used
Thionyl chloride replaces the –OH of a carboxylic acid or alcohol with chlorine. RCOOH + SOCl₂ gives RCOCl, with SO₂ and HCl leaving as gases that are scrubbed, so the acid chloride is ready for the next coupling step.
Tested
Each batch is reported on a COA covering appearance, identification, assay and the agreed impurity limits, such as sulphuryl chloride and sulphur chlorides. Samples are drawn and sealed under dry conditions, so your QC team can check them and release the lot quickly.
Stored
Moisture turns it into HCl and SO₂, which corrode steel and build pressure inside containers. Keep drums tightly closed, cool and dry, blanket them with dry inert gas once opened, and store them away from water, alcohols, bases and metals.
Glossary
Terms you will meet on quotations, specifications and documents for Thionyl Chloride.
FAQ
Anything else, call +91 98191 11179 or write to source@chelorapharmachem.com.
Request a QuoteThionyl chloride (CAS 7719-09-7) is a chlorinating agent. It converts carboxylic acids into acid chlorides and alcohols into alkyl chlorides for API, agrochemical, dye and pigment synthesis. It is also the cathode material and electrolyte in lithium–thionyl chloride batteries, and a reagent in fine-chemical and laboratory work.
The CAS number is 7719-09-7, and the EC number is 231-748-8. Its formula is SOCl₂ and its molar mass is 118.97 g/mol. Quoting the CAS number on your enquiry avoids confusion with sulphuryl chloride, which has a similar name.
Yes. Thionyl chloride, thionyl dichloride, sulphinyl chloride (sulfinyl dichloride) and sulphurous oxychloride are all names for the same substance, SOCl₂, with CAS 7719-09-7 and EC 231-748-8.
Thionyl chloride is SOCl₂ (CAS 7719-09-7), with sulphur in the +4 state, and is mainly used to make acid chlorides and alkyl chlorides. Sulphuryl chloride is SO₂Cl₂ (CAS 7791-25-5), with sulphur in the +6 state, and is used mostly for chlorinating aromatic rings and other carbon–hydrogen positions. They are not interchangeable.
We supply technical and synthesis grades (typically assay ≥ 99%) and higher-purity material on enquiry, subject to availability. Tell us your application, purity, impurity limits and preferred packing when you enquire, especially for battery or sensitive API use.
Keep it in tightly closed, corrosion-resistant containers in a cool, dry, well-ventilated and locked store, below about 30 °C, away from water, moist air, alcohols, amines, bases and metals. Use dry inert gas once a container is opened, and follow the storage section of the SDS supplied with the batch.
Thionyl chloride has its own HS subheading, 2812.17, under halides and halide oxides of non-metals. In India it is generally declared under 2812 17 00. Confirm the full national tariff code with your customs broker before import or export.
Yes. It is toxic if inhaled, harmful if swallowed, and causes severe skin burns and eye damage. It reacts violently with water, releasing hydrogen chloride and sulphur dioxide. Read the SDS before handling, work in closed systems with gas scrubbing, and wear full face, hand and body protection.
Yes. It is regulated as UN 1836, Thionyl chloride, Class 8 (corrosive), Packing Group I for road and sea, and air transport is generally not permitted. Always check the transport section of the SDS supplied with the batch.
It is listed in Schedule 3 of the Chemical Weapons Convention, which covers chemicals with large legitimate industrial uses. Trade is monitored, so imports and exports may need end-use or end-user documents. We share the paperwork needed for each supply and may ask you to confirm the intended use.
We provide a batch-wise Certificate of Analysis (COA), SDS/MSDS and specifications. Additional documents for vendor qualification can be arranged on request.
Yes. We handle requirements from samples and trial lots for R&D, process development and vendor approval up to regular bulk supply for commercial production, subject to product availability and dangerous-goods packing rules.
We supply buyers across India, including Maharashtra, Gujarat, Telangana, Andhra Pradesh, Himachal Pradesh, Goa, Karnataka, Tamil Nadu, Madhya Pradesh, Uttarakhand and Sikkim, from our centralized sales office in Mumbai.
Email source@chelorapharmachem.com or source@cheloragroup.com, call +91 98191 11179, or use the enquiry form on this page. Include the quantity, grade, delivery location and target date.
Request a Quote
Tell us the quantity, grade and delivery location. Our centralized sales team replies with competitive pricing, lead time and documentation.
