Ethylating Agent · Dyes · APIs · Quats
Diethyl sulfate (DES), the liquid ethylating agent that puts ethyl groups onto phenols, amines and thiols for dyes, APIs, agrochemicals and quats. Sourced and supplied by Chelora Pharmachem, Mumbai, and delivered across India with a batch COA and SDS.
How Buying Works
Send the quantity, grade (technical or synthesis), packing, delivery city and target date. Quote CAS 64-67-5 so there is no confusion with dimethyl sulphate.
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 testing, ethylation trials and vendor qualification before your commercial order.
Packed, labelled and sent with invoice, batch COA and transport documents. Repeat orders are planned with you.
Product Overview
Diethyl Sulfate (diethyl sulphate, DES, sulphuric acid diethyl ester; CAS 64-67-5) is the diethyl ester of sulphuric acid, (C2H5O)2SO2. It is a clear, colourless, oily liquid with a faint ethereal, peppermint-like odour that boils at about 208–209 °C with decomposition. As a strong, direct-acting alkylating agent it transfers an ethyl group to oxygen, nitrogen and sulphur atoms, which makes it a standard industrial ethylating agent for dye, pharmaceutical, agrochemical and surfactant chemistry, handled in closed plant systems.
The largest use of diethyl sulphate is in dyes, pigments and textile chemicals, where it ethylates amines and phenols and quaternises dye bases. Pharmaceutical and fine-chemical plants use it to make ethyl ethers, N-ethyl amines and ethyl thioethers, and surfactant makers use it to turn tertiary amines into ethosulphate quaternary ammonium salts for conditioners, softeners and antistatic agents. It is liquid, high-boiling and low in cost per ethyl group, so it is often chosen over ethyl bromide or ethyl iodide, but it is also a probable human carcinogen and must be handled with care.
As a chemical supplier in Mumbai, Chelora Pharmachem supplies diethyl sulphate to API, intermediate, dye, agrochemical and surfactant buyers across India, with a batch-wise COA, SDS/MSDS and specification, packed in sealed UN-approved containers and shipped as a toxic dangerous good under UN 1594. Our team can advise on pack sizes, lead times and the transport documents your stores and EHS teams need. For methylation rather than ethylation we also supply Dimethyl Sulfate, the methyl analogue.
In Depth
Diethyl sulphate is a neutral ester in which both acidic hydrogens of sulphuric acid are replaced by ethyl groups. The sulphate group is an excellent leaving group, so the ethyl carbons are electrophilic and readily attacked by nucleophiles. It is only slightly soluble in water and hydrolyses slowly to ethyl hydrogen sulphate and ethanol, and eventually to sulphuric acid.
Phenoxides give ethyl aryl ethers, amines give N-ethyl amines, thiolates give ethyl thioethers and tertiary amines give quaternary ammonium ethosulphates. The first ethyl group transfers readily under mild, usually basic conditions; the second reacts far more slowly, so most processes use one ethyl group per mole and leave ethyl sulphate salts in the effluent. Water, heat and pH control decide the yield.
Commercial diethyl sulphate is made from ethylene and concentrated sulphuric acid, which first form ethyl hydrogen sulphate; it also occurs as an intermediate in the older strong-acid process for synthetic ethanol. Other routes start from ethanol with sulphuric or chlorosulphonic acid. The crude ester is washed and purified by vacuum distillation to limit acidity, ethyl hydrogen sulphate and ether.
Dye chemistry is the main outlet for diethyl sulphate. It converts aromatic amines into N-ethyl and N,N-diethyl intermediates, ethylates phenolic groups and quaternises heterocyclic dye bases to give cationic (basic) dyes for acrylic fibres. Textile auxiliary makers also use it for ethosulphate finishing agents. Purity and low acidity help keep shade, yield and by-products consistent.
Confirm the grade and pack size first, then compare GC purity, appearance and colour, free acidity as H₂SO₄, ethyl hydrogen sulphate, water and density. Ask how the drums are lined and sealed, since moisture causes slow hydrolysis and acid build-up. Because diethyl sulphate is a carcinogen, your EHS team will also want the SDS, exposure controls and waste plan before the first delivery.
Chelora Pharmachem supplies diethyl sulphate (CAS 64-67-5) from its centralized sales office in Mumbai to API, intermediate, dye, agrochemical and surfactant buyers across India. Share the grade, quantity, packing and delivery location, and our team replies with price, lead time, dangerous-goods transport arrangements and documents, from small trial lots for process development to regular supply for commercial campaigns.
Global Sourcing
Our focus is the Indian market. When local supply is short, or you need a specific origin, grade or pack size, our international sourcing desk brings diethyl sulphate 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 200-589-6. Also sold as diethyl sulphate, DES or sulphuric acid diethyl ester.
A central sulphur with two S=O bonds and two ethoxy (–OC₂H₅) groups.
Appearance
Clear, colourless oily liquid with a faint ethereal, peppermint-like odour. Flash point about 104 °C.
Solubility
About 7 g/L in water at 20 °C, with slow hydrolysis. Miscible with ethanol and ether.
Technical Data
Reference data for Diethyl Sulfate, useful when writing a specification, checking an SDS or planning storage and transport.
| Property | Value |
|---|---|
| IUPAC name | Diethyl sulfate |
| Synonyms | Diethyl sulphate, DES, ethyl sulfate, sulphuric acid diethyl ester, diethyl tetraoxosulfate |
| CAS number | 64-67-5 |
| EC number | 200-589-6 |
| PubChem CID | 6163 |
| Molecular formula | C4H10O4S ((C2H5O)2SO2) |
| Molar mass | 154.18 g/mol |
| Appearance | Clear, colourless oily liquid; faint ethereal, peppermint-like odour |
| Melting point | About −25 °C (freezing point) |
| Boiling point | About 208–209 °C, with decomposition |
| Density | About 1.18 g/cm³ at 20 °C |
| Refractive index | About 1.40 (nD at 20 °C) |
| Flash point | About 104 °C (closed cup); auto-ignition about 436 °C |
| Vapour pressure | About 0.25 hPa at 20 °C; vapour about 5.3 times heavier than air |
| Solubility in water | About 7 g/L at 20 °C, with slow hydrolysis to ethyl hydrogen sulphate and ethanol |
| Other solvents | Miscible with ethanol and diethyl ether; soluble in most organic solvents |
| HS code | 2920 29 20 (Diethyl sulphate) in India’s Customs Tariff; other countries may use 2920.90. Confirm with your broker |
| Transport | UN 1594, Diethyl sulphate, Class 6.1 (toxic), Packing Group II |
Literature values for reference. Supplied material is tested batch-wise and reported on the COA.
Applications
Diethyl sulphate is a reagent, not an ingredient: it adds ethyl groups to oxygen, nitrogen and sulphur in dye, API, surfactant and agrochemical routes.
The main industrial use. Diethyl sulphate makes N-ethyl and N,N-diethyl aniline-type intermediates, ethylates phenolic dye components and quaternises dye bases into cationic dyes for acrylic fibres. Textile auxiliary makers also use it for ethosulphate finishing and antistatic agents.
Main industrial use
In pharmaceutical synthesis, diethyl sulphate ethylates phenols to aryl ethyl ethers, amines to N-ethyl amines and heterocyclic nitrogens to N-ethyl derivatives. API makers choose it when a liquid, high-boiling, lower-cost ethylating agent fits the process and genotoxic-impurity controls are in place.
Ethylation step
Tertiary amines and amidoamines react with diethyl sulphate to give quaternary ammonium ethosulphates. These cationic surfactants are used as conditioning agents in hair care, as fabric softeners and as antistatic agents, often as an alternative to methosulphate quats.
Cationic surfactants
Crop-protection chemistry uses diethyl sulphate to introduce ethyl ether, N-ethyl and S-ethyl groups into intermediates for herbicides, insecticides and fungicides. It is used at the intermediate stage, not in formulations, and buyers specify purity and acidity to keep side reactions low.
Crop protection
Fine-chemical and aroma producers use diethyl sulphate to make ethyl aryl ethers such as phenetole, ethyl thioethers and other ethyl derivatives. It is also used as an accelerator in some sulphation reactions and as an ethylating reagent in research and ionic-liquid synthesis.
Synthesis 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 Diethyl Sulfate.
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.
Harmful if swallowed, in contact with skin or if inhaled, causes severe skin burns and eye damage, may cause genetic defects and may cause cancer (EU harmonised Carc. 1B, Muta. 1B). Signal word: Danger. IARC lists it as probably carcinogenic to humans (Group 2A). Check the SDS of the batch for the classification that applies.
H302H312H314H332H340H350
Handle only in closed systems or under efficient local exhaust, and get special instructions before use. Wear chemical goggles with a face shield, chemical-resistant gloves, protective clothing and suitable respiratory protection where vapour or mist can escape. Keep an emergency shower and eyewash nearby.
Store locked up in a cool, dry, well-ventilated place, in tightly closed original containers, away from heat, direct sunlight, moisture, strong bases, oxidisers, amines and ammonia. Keep it away from food and feed, and restrict access to trained staff.
Regulated as UN 1594, Diethyl sulphate, Class 6.1 (toxic), Packing Group II, for road, sea and air. It needs UN-approved packaging, toxic labels and dangerous-goods documents. Confirm the details with the batch SDS and your forwarder.
Evacuate and ventilate the area and wear full protective equipment. Absorb the liquid with dry, inert material, collect it in closed, labelled containers for disposal as hazardous waste, and keep it out of drains and water courses. Small residues can be destroyed with dilute alkali under controlled conditions.
PAN India Delivery
From our centralized sales office in Mumbai, we supply Diethyl Sulfate 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 technical or synthesis-grade diethyl sulphate used in dye, API and surfactant work. Share your in-house specification and we quote against it.
The Chemistry
Made
Ethylene is absorbed in concentrated sulphuric acid to give ethyl hydrogen sulphate, which is converted to diethyl sulphate. The crude ester is neutralised, washed and vacuum-distilled, which keeps free acid, ethyl hydrogen sulphate and diethyl ether under control.
Used
A phenoxide, amine or thiolate attacks an ethyl carbon and displaces ethyl sulphate, forming a new O-, N- or S-ethyl bond. With tertiary amines the product is a quaternary ammonium ethosulphate. A base is usually added to take up the acid formed.
Tested
Each batch is reported on a COA covering appearance, identification, GC purity and the other parameters agreed with you, such as acidity, ethyl hydrogen sulphate, water and colour, so your QC team can release it quickly against your specification.
Stored
Moisture slowly hydrolyses diethyl sulphate to ethyl hydrogen sulphate and sulphuric acid, which corrodes metal and degrades quality. Keep drums tightly closed in a cool, dry, ventilated and locked store, and follow the SDS for handling and exposure control.
Glossary
Terms you will meet on quotations, specifications and documents for Diethyl Sulfate.
FAQ
Anything else, call +91 98191 11179 or write to source@chelorapharmachem.com.
Request a QuoteDiethyl sulphate (CAS 64-67-5) is an ethylating agent. It is used mainly to make dyes, pigments and textile chemicals, and also for API and drug intermediates, quaternary ammonium ethosulphate surfactants, agrochemical intermediates and ethyl ethers, amines and thioethers in fine-chemical synthesis.
The CAS number is 64-67-5 and the EC number is 200-589-6. Its formula is C4H10O4S and its molar mass is 154.18 g/mol. Quoting the CAS number avoids confusion with dimethyl sulphate (77-78-1) and with ethyl hydrogen sulphate.
Yes. Diethyl sulphate is the British spelling and diethyl sulfate the American one. DES, ethyl sulfate and sulphuric acid diethyl ester are other names for the same substance, CAS 64-67-5. Whatever name is on your purchase order, quoting the CAS number confirms the product.
Dimethyl sulphate (CAS 77-78-1) transfers methyl groups, while diethyl sulphate (CAS 64-67-5) transfers ethyl groups, so they give different products. Dimethyl sulphate is also far more acutely toxic, fatal if inhaled, and ships as UN 1595 in Packing Group I; diethyl sulphate ships as UN 1594 in Packing Group II.
All three are ethylating agents. Diethyl sulphate is a high-boiling liquid (about 209 °C) that is lower in cost per ethyl group and easy to handle in closed plants. Ethyl bromide (bp about 38 °C) and ethyl iodide (bp about 72 °C) are volatile and costlier but suit some reactions. Your process chemists should decide on trial results.
We supply technical grade and synthesis grade (typically 99% minimum by GC), subject to availability. Tell us the grade, pack size and any limits on acidity, ethyl hydrogen sulphate or water when you enquire, and we quote against your specification.
Keep it in tightly closed original containers in a cool, dry, well-ventilated and locked store, away from heat, sunlight, moisture, strong bases, oxidisers and amines, and away from food and feed. Restrict access to trained staff and follow the storage section of the batch SDS.
In India’s Customs Tariff, diethyl sulphate has its own tariff item, 2920 29 20. Older Indian records and many other countries’ tariffs use lines under 2920.90. Confirm the full national tariff code with your customs broker before import or export.
Yes. It is harmful if swallowed, inhaled or absorbed through skin, causes severe skin burns and eye damage, and is classified as a mutagen and carcinogen (Category 1B; IARC Group 2A). Read the SDS before handling and use closed systems, local exhaust, eye and face protection, gloves and respiratory protection.
Yes. It is shipped as UN 1594, Diethyl sulphate, Class 6.1 (toxic), Packing Group II. It needs UN-approved packaging, toxic labels and dangerous-goods documents. Always check the transport section of the SDS supplied with the batch.
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 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.
