Diethyl Sulfate Sulfuric Acid Diethyl Ester · CAS 64-67-5
Chelora Chemicals is a supplier of Diethyl Sulfate, the industrial ethylating agent used across dye, pharmaceutical and agrochemical synthesis. Every consignment leaves with a batch-specific COA and the current SDS, and is shipped as the regulated toxic liquid it is.
Also known as: DES · Diethyl Sulphate · Ethyl Sulfate · Sulfuric Acid Diethyl Ester
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Price, lead time and a sample COA for Diethyl Sulfate, usually within one working day. We ship worldwide under full dangerous-goods documentation.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (assay, water content, free acidity)
- Safety Data Sheet (SDS)
- Dangerous-goods transport documents (Class 6.1)
- Third-party inspection on request
- Certificate of origin
What is Diethyl Sulfate?
Diethyl Sulfate, the diethyl ester of sulfuric acid, is a colourless to pale, oily liquid with a faint ether-like odour, formula C₄H₁₀O₄S. It is one of the most widely used industrial ethylating agents, valued for transferring an ethyl group cleanly onto phenols, amines, thiols and other nucleophiles in a single, well-controlled reaction step.
That reactivity is the entire commercial case for the material: a chemist needing to install an ethyl group — on a dye intermediate, a pharmaceutical building block, or an agrochemical active — reaches for diethyl sulfate because it is a reliable, scalable alkylating agent with decades of established process chemistry behind it. It is also used as an accelerator in the sulfation of ethylene and in certain sulfonation processes.
Commercially, it is manufactured by reacting ethanol with sulfuric acid or oleum under controlled conditions, followed by purification to the assay and free-acidity limits the downstream chemistry requires.
Diethyl Sulfate is classified as a toxic liquid (UN 1594, Class 6.1) and carries carcinogenicity and mutagenicity hazard statements under GHS. It is a controlled, closely regulated material, and it is supplied, packed and transported accordingly — not treated as a routine solvent.
Why Diethyl Sulfate specifically
- A dependable ethylating agent. Reacts cleanly with phenols, aromatic amines and thiols to install an ethyl group where the target molecule needs one.
- Established process chemistry. Decades of industrial use in dye and pharmaceutical synthesis mean the handling, dosing and workup chemistry is well understood.
- A sulfation and sulfonation accelerator. Used to speed selected sulfation reactions, including the sulfation of ethylene, and in certain sulfonation processes.
- Scales from lab to plant. The same ethylation chemistry that works on a bench scale is run at full production scale in dye, pharma and agrochemical plants worldwide.
How Diethyl Sulfate is Manufactured
Diethyl Sulfate is made on a dedicated, tightly controlled process line, reflecting both the reaction chemistry involved and the regulatory handling the material demands from the first production step onward.
- Esterification. Ethanol is reacted with concentrated sulfuric acid or oleum under controlled temperature and concentration, forming the diethyl ester.
- Reaction control. Conditions are held tightly to limit mono-ethyl sulfate and free-acid carryover, both of which affect downstream reactivity.
- Purification. The crude ester is purified to the target assay, typically 99.5% minimum, with water content and free acidity reduced to specification.
- Quality release. Assay, water content, free acidity and specific gravity are confirmed against specification before the batch is released.
- Finishing and packing. The purified liquid is packed into UN-rated drums or bulk containers under Class 6.1 dangerous-goods handling conditions.
Typical Commercial Specification
Figures below are representative of commercial-grade Diethyl Sulfate. Tell us your downstream ethylation chemistry and the grade you need, and we will advise on the specification to order against.
| Parameter | Typical Value |
|---|---|
| Appearance | Colourless to pale, clear oily liquid |
| Diethyl Sulfate content | 99.5% min |
| Water content | 0.1% max |
| Free acidity (as H₂SO₄) | 0.2% max |
| Specific gravity (20/20 °C) | 1.176 – 1.182 |
| Colour (APHA) | 10 max |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | C₄H₁₀O₄S |
| Molecular weight | 154.18 g/mol |
| Appearance | Colourless to pale oily liquid |
| Odour | Faint ether-like odour, irritating after-effect |
| Melting point | About −24.5 °C |
| Boiling point | About 208 °C (decomposes) |
| Density | About 1.177 – 1.182 g/mL (20 °C) |
| Flash point | About 104 – 121 °C (closed cup) |
| Refractive index | About 1.399 – 1.402 |
| Vapour pressure | About 0.29 mmHg |
| Solubility | Soluble in alcohol and ether; reacts with water |
| Incompatibilities | Water and moisture (slow hydrolysis); strong bases; oxidisers; ammonia and amines (exothermic reaction) |
Behaviour in the process
Diethyl Sulfate's reactivity is what synthetic and process chemists are buying:
- Ethylating power. Reacts as an electrophilic ethylating agent toward phenols, aromatic amines, thiols and other nucleophiles, installing an ethyl group in a controlled, scalable step.
- Sulfation accelerator. Used to accelerate selected sulfation reactions, including the sulfation of ethylene, and in certain sulfonation processes.
- Moisture sensitivity. Hydrolyses slowly in the presence of water to give ethanol and sulfuric acid, so dry handling and storage protect both yield and equipment.
- High toxicity. Classified as toxic in contact with skin, harmful if swallowed or inhaled, and carrying carcinogenicity and mutagenicity hazard statements — handling demands engineering controls, not just PPE.
Diethyl Sulfate and Related Alkylating Agents
Diethyl Sulfate is one of several industrial alkylating agents, and the choice between them depends on which alkyl group the target synthesis needs and the toxicity and handling profile a plant is set up for.
| Material | Alkyl group installed | When it is the right choice |
|---|---|---|
| Diethyl Sulfate | Ethyl | Routes needing a clean, scalable ethylation of phenols, amines or thiols |
| Dimethyl Sulfate | Methyl | Routes needing a methyl rather than an ethyl group; a comparably reactive and comparably regulated agent |
| Ethyl Chloride / Ethyl Bromide | Ethyl | Routes using alkyl halide chemistry rather than a sulfate ester, often at lower reactivity |
| Diethyl Carbonate | Ethyl (milder) | Routes needing a safer, lower-toxicity ethylating agent at the cost of slower reaction rates |
Stated plainly: diethyl sulfate earns its place where the target molecule specifically needs an ethyl group installed at scale — a route needing methylation, or a route that can tolerate a slower, lower-toxicity reagent, points toward a different alkylating agent.
Industries We Supply Diethyl Sulfate To
The same ethylating agent feeds a dye manufacturer, a pharmaceutical intermediate plant and an agrochemical producer. What changes is the downstream ethylation target and the documentation each requires.
Where Diethyl Sulfate is Used
Diethyl Sulfate is bought almost entirely as a process ethylating agent. These are the downstream chemistries our customers use it for.
In dye and pharmaceutical synthesis
Diethyl Sulfate is dosed under controlled temperature and pH to ethylate a phenol, amine or thiol intermediate, typically in the presence of a base to neutralise the sulfuric acid co-product. Free acidity and water content on the COA matter here because both can affect conversion and by-product formation in the ethylation step.
In agrochemical and specialty-chemical synthesis
The same ethylation chemistry installs the ethyl group a crop-protection active or a specialty surfactant needs, and the material is also used more broadly as a dehydrating agent and process reagent in industrial synthesis outside pure ethylation chemistry.
Need a specific purity or packing format?
Tell us the purity you need, your downstream ethylation chemistry, the packing format you can receive and the annual quantity. We will come back with a price, a lead time and a sample COA.
Quality Control & Testing
Every lot is released against a batch-specific Certificate of Analysis, with free acidity and water content reported alongside assay because both affect downstream ethylation performance.
- Diethyl Sulfate assay — the primary grade measure, typically 99.5% minimum.
- Free acidity (as H₂SO₄) — reported because residual acid can interfere with ethylation and attack process equipment.
- Water content — measured because moisture drives slow hydrolysis of the ester in storage and transit.
- Specific gravity and colour (APHA) — fast purity and identity checks.
Common Process Problems & Likely Causes
When this reagent causes trouble, it is usually free acidity or moisture. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| Reduced ethylation yield | Moisture-driven hydrolysis of the ester before dosing | Water content on the COA and storage/transfer conditions |
| Excess acid in the reaction mass | Free acidity above the specification limit | Free acidity (as H₂SO₄) figure on the COA |
| Slower-than-expected reaction | Low assay or diluted lot | Assay and specific gravity on the COA |
| Equipment corrosion | Free sulfuric acid carried over from manufacture | Free acidity figure and material compatibility of your reaction vessel |
Packaging, Storage & Shipping
- Standard packing. UN-rated HDPE or lined steel drums, typically 25 – 250 kg net, with larger bulk/tank formats on contract supply.
- Moisture exclusion. Keep sealed and dry; the ester hydrolyses slowly in contact with water or humid air.
- Temperature control. Store at room temperature or cooler, away from direct sun and heat sources.
- Material compatibility. Avoid contact with strong bases, amines, ammonia and oxidisers, all of which react exothermically.
- Shelf life. Stable in sealed, dry containers under normal storage conditions; re-test on prolonged storage.
- Transport classification. UN 1594, toxic liquid, Class 6.1, Packing Group II. ADR, IMDG, IATA and DOT requirements apply to packing, labelling and routing.
Hazards & Safe Handling
Diethyl Sulfate is classified as toxic in contact with skin, harmful if swallowed or inhaled, corrosive to skin and eyes, and carries hazard statements for genetic defects (mutagenicity) and cancer (carcinogenicity) under GHS. It is a controlled industrial chemical that requires engineering controls, not routine PPE alone.
- Skin and eye contact. Causes severe burns and is toxic through skin contact; chemical-resistant gloves, goggles and a face shield are a baseline, with immediate water rinsing on contact.
- Inhalation. Handle only in closed systems or under local exhaust ventilation; vapour is harmful if inhaled.
- Carcinogenicity and mutagenicity. Classified as a suspected carcinogen and mutagen; handling should follow your site's controls for CMR (carcinogenic, mutagenic, reprotoxic) substances.
- PPE and engineering controls. Closed transfer systems, fume-hood or local-exhaust handling, chemical-resistant gloves and full-face protection, with a documented site exposure-control plan.
- Environment. Avoid uncontrolled release to water or soil; follow local effluent and waste-disposal rules for a hazardous ester.
Regulatory & Compliance Notes
Diethyl Sulfate is a registered, closely regulated industrial chemical shipped as a Class 6.1 toxic liquid. Because obligations differ by territory and use — including controls specific to CMR substances — the notes below are orientation rather than legal advice; confirm your own position with your regulatory adviser.
- GHS classification. Classified as toxic, corrosive, mutagenic and carcinogenic; the SDS carries the full hazard statements for your grade.
- REACH and chemical inventories. Registered under EU REACH as a substance of concern and listed on major chemical inventories.
- Dangerous goods transport. UN 1594, toxic liquid, Class 6.1, Packing Group II. ADR, IMDG, IATA and DOT requirements apply to packing, labelling and routing.
- HS code. Commonly declared under the esters of other inorganic acids heading; confirm the exact tariff line with your customs broker for your jurisdiction.
- Site and licensing checks. Many jurisdictions require a receiving site to be licensed or registered to handle a CMR-classified toxic liquid. Confirm your site's status before placing an order.
We Supply Diethyl Sulfate Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Diethyl Sulfate from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the dangerous-goods export documentation and freight so the material arrives ready to use.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged as routing allows.
- Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and full dangerous-goods transport documents issued as a complete set.
- Flexible volumes. From drum trial quantities up to repeat bulk shipments on a supply contract.
- Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.
Buying Diethyl Sulfate from Chelora
We are an independent sourcing and supply partner. For this product that means settling three things at enquiry: the assay and free-acidity tolerance your ethylation chemistry needs, the packing format, and the quantity you are buying, all within the dangerous-goods documentation the shipment requires.
- Documentation on every lot. Batch-specific COA with assay, free acidity and water content, plus the current SDS and DG transport paperwork.
- Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
- Quantities. Drum trial quantities through to larger bulk shipments on contract supply.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related building blocks. Other fluorinated and dye-intermediate building blocks alongside this product from one supplier.
How ordering works
- Send the enquiry. Purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
- We quote. Price, lead time, packing format and a sample COA, normally within one working day.
- Qualify the supply. For first orders or pharma-grade applications, we share the analysis so your technical team can sign off before you commit.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
- Ship and document. Packed, labelled and loaded with the full export and dangerous-goods document set, and tracked through to arrival.
Diethyl Sulfate — Common Questions
The questions our technical desk is asked most often about Diethyl Sulfate. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of Diethyl Sulfate?
The CAS number for Diethyl Sulfate is 64-67-5, and its EC number is 200-589-6. Its molecular formula is C₄H₁₀O₄S with a molecular weight of 154.18 g/mol.
What is Diethyl Sulfate used for?
Mainly as an ethylating agent in dye, pharmaceutical and agrochemical synthesis, and as an accelerator in selected sulfation and sulfonation reactions, including the sulfation of ethylene.
Do you supply Diethyl Sulfate worldwide?
Yes. Chelora Chemicals supplies and exports Diethyl Sulfate worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India. Every consignment carries the COA, the SDS and full Class 6.1 dangerous-goods transport documentation.
How is Diethyl Sulfate manufactured?
By reacting ethanol with concentrated sulfuric acid or oleum under controlled temperature and concentration, followed by purification to the assay, water-content and free-acidity limits the grade requires.
Is Diethyl Sulfate hazardous?
Yes. It is classified as toxic in contact with skin, harmful if swallowed or inhaled, corrosive to skin and eyes, and carries GHS hazard statements for mutagenicity (H340) and carcinogenicity (H350). It requires engineering controls and trained handling, not routine PPE alone.
What are the UN number and transport class?
UN 1594, toxic liquid, Class 6.1, Packing Group II. ADR, IMDG, IATA and DOT rules apply to packing, labelling and routing, and most jurisdictions require the receiving site to be licensed to handle a CMR-classified toxic liquid.
How should Diethyl Sulfate be stored?
In sealed, dry containers at room temperature or cooler, away from direct sun, heat, strong bases, amines and oxidisers. Moisture exclusion matters because the ester hydrolyses slowly on contact with water.
Why does free acidity matter for this product?
Residual sulfuric acid left over from manufacture can interfere with downstream ethylation chemistry and corrode process equipment. That is why free acidity (as H₂SO₄) is specified and tested on every lot.
What purity grades do you offer?
Standard commercial grade is 99.5% minimum assay, with water content and free acidity reported on the COA. Reagent-grade material around 98–99.6% is also available for lower-volume or research requirements.
Is Diethyl Sulfate the same as Dimethyl Sulfate?
No. Both are sulfate-ester alkylating agents with a similar hazard profile, but Diethyl Sulfate installs an ethyl group while Dimethyl Sulfate installs a methyl group. The choice depends on which substituent your target molecule needs.
What packing sizes and order quantities are available?
UN-rated HDPE or lined steel drums, typically 25–250 kg net, with larger bulk or tank formats available on contract supply. Orders run from trial quantities up to repeat bulk loads.
Ready to source Diethyl Sulfate?
Send us your purity requirement and annual volume. You will get a price, a realistic lead time and a sample COA from someone who understands what the material has to do in your process — delivered anywhere in the world under full dangerous-goods documentation.