Skip to content
Industrial Ethylating Agent · CAS 64-67-5

Diethyl Sulfate

(C2H5)2SO4 Molar mass 154.19 g/mol

The industrial ethylating agent supplied by Chelora Chemicals — known in the trade as DES, used under strictly controlled conditions to introduce ethyl groups in dye and fine-chemical synthesis — exported from Indonesia in drums and ISO tanks with full batch documentation and dedicated handling protocols on every shipment.

Identification Sheet REP.
IUPAC nameDiethyl Sulfate
CAS number64-67-5
Molecular formula(C₂H₅)₂SO₄
Molar mass154.19 g/mol
AppearanceColourless to pale yellow oily liquid, faint peppermint-like odour
Common synonymsDES, Diethyl Sulphate, Sulfuric Acid Diethyl Ester
Melting Point−26 °Clit.
Boiling Point210 °Cat 1 atm, decomposes
Specific Gravity1.18at 20 °C
Flash Point104 °Cclosed cup
AppearanceColourless to pale yellow oily liquidfaint peppermint-like odour
Purity Offered99%+technical/industrial grade
01 / PRODUCT DOSSIER

What Diethyl Sulfate is, and why buyers source it

A working overview of the compound's chemistry, its role as a powerful industrial ethylating agent, and the grade Chelora Chemicals keeps in regular supply, together with the strict handling discipline this chemical requires.

Diethyl Sulfate is the diethyl ester of sulfuric acid, the direct ethyl-group analogue of dimethyl sulfate. Its two ethyl groups are strongly electrophilic and readily transferred to nucleophiles such as amines, phenols and carboxylate ions, giving it the same class of efficient alkylating reactivity as dimethyl sulfate, though generally somewhat less reactive given the larger, more sterically hindered ethyl group.

At room temperature it is a colourless to pale yellow, oily liquid with a faint, peppermint-like odour that, as with dimethyl sulfate, is not a reliable warning of hazardous exposure levels. It reacts slowly with atmospheric moisture to release ethanol and sulfuric acid, and must be stored and handled under strictly controlled, moisture-free, well-ventilated conditions with dedicated engineering controls.

Where it fits in the synthesis chain

Diethyl Sulfate's primary industrial use, like dimethyl sulfate, is as an ethylating agent in the synthesis of dyes, pharmaceutical intermediates and fine chemicals, where an ethyl group rather than a methyl group is specifically required for the target molecule. It is used only by facilities with the specialised containment, scrubbing and emergency-response infrastructure this reagent requires, strictly under closed-system handling.

Grade we supply

Chelora Chemicals offers Diethyl Sulfate in technical/industrial grade (99%+ assay) supplied exclusively to buyers with verified closed-system handling capability and full regulatory authorisation, accompanied by a batch-wise certificate of analysis and complete safety documentation.

02 / MANUFACTURING ROUTE

How Diethyl Sulfate is made

An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.

Diethyl Sulfate is manufactured by reacting ethanol with sulfur trioxide (or oleum/chlorosulfonic acid, depending on the specific process route) under carefully controlled conditions: 2 C₂H₅OH + SO₃ → (C₂H₅)₂SO₄ + ... (process-specific by-products). The reaction is run in specialised, fully enclosed equipment with integrated scrubbing systems given the product's hazard profile, and the crude product is purified by vacuum distillation.

Why this remains a tightly controlled, specialist manufacturing process

As with dimethyl sulfate, because diethyl sulfate is both the product and, if mishandled, an acute hazard in its own right, its manufacture is run exclusively in dedicated, fully enclosed plant with continuous containment and scrubbing, a very different operating discipline from most of the commodity chemicals in this catalogue.

03 / APPLICATIONS

Industries and processes that use it

Diethyl Sulfate is consumed in specialist fine-chemical and dye methylation (here, ethylation) reactions, always under closed-system, tightly controlled conditions. The fields below account for the demand we see through our export desk, restricted to verified industrial buyers.

Field 01

Dye & Pigment Intermediate Ethylation

Used to introduce ethyl groups onto amine and phenolic intermediates in dye and pigment synthesis, under closed-system reactor conditions.

Field 02

Pharmaceutical Intermediate Ethylation

Used in selected pharmaceutical fine-chemical synthesis routes requiring an efficient O- or N-ethylation step, under full regulatory and safety oversight.

Field 03

Agrochemical Intermediate Ethylation

Used to ethylate selected agrochemical intermediates in closed-system industrial synthesis.

Field 04

Specialty Fine-Chemical Synthesis

Used in limited specialty fine-chemical ethylation applications under the same strict closed-system handling discipline.

04 / REACTION CHEMISTRY

How the molecule is typically carried forward

The electrophilic ethyl-sulfate linkage governs almost all of this molecule's reaction chemistry. Reaction classes below account for most of the ways Diethyl Sulfate is used as an ethylating reagent.

Nucleophilic Ethylation (Primary Reaction)

A nucleophile (amine nitrogen, phenolic oxygen, or similar) attacks an ethyl group on the sulfate centre, transferring the ethyl group and releasing ethyl sulfate anion, the core reaction behind all of DES's industrial uses.

Hydrolysis (Degradation Pathway)

Reacts slowly with atmospheric or adventitious moisture to release ethanol and sulfuric acid, a pathway that must be prevented during storage and handling.

Double Ethylation (Process Chemistry)

Can transfer both ethyl groups sequentially in some reaction schemes, a consideration in reaction stoichiometry and by-product management.

Sulfating Esterification (Upstream)

Ethanol reacts with sulfur trioxide under closed-system conditions to form diethyl sulfate itself, the dominant industrial route in the whole chain.

05 / RELATED BUILDING BLOCKS

Diethyl Sulfate against other amines we supply

Buyers sourcing Diethyl Sulfate for verified, closed-system ethylation applications often need the related methylating agent. A quick reference to what else is on our regular supply list, subject to the same strict handling verification.

ProductCAS NumberCategoryNotes
Diethyl Sulfate64-67-5Industrial ethylating agentThe product on this page — supplied exclusively to verified closed-system industrial users.
Dimethyl Sulfate77-78-1Industrial methylating agentThe related methylating agent used in similar fine-chemical synthesis — see its product page.
Methanol67-56-1Simplest aliphatic alcoholThe alcohol-chemistry feedstock analogous to the ethanol used for DES — see its product page.
Caustic Soda (Sodium Hydroxide)1310-73-2Industrial alkaliUsed for controlled neutralisation/deactivation of DES process streams — see its product page.

Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than Diethyl Sulfate.

06 / HAZARD & HANDLING

Safety classification at a glance

Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.

H301

Toxic if swallowed.

H311

Toxic in contact with skin.

H331

Toxic if inhaled.

H351

Suspected of causing cancer.

PPE Standard

Full-face supplied-air respiratory protection, chemical-resistant totally encapsulating suits and closed-system transfer equipment are mandatory — no open handling is permitted.

Acute Toxicity Precaution

Toxic by inhalation with effects that can be delayed; any suspected exposure is a medical emergency requiring immediate professional care.

Carcinogenicity Precaution

Suspected of causing cancer; exposure must be eliminated through engineering controls, not managed through PPE alone.

Signal word

Danger — GHS06 acute toxicity and GHS08 carcinogen/health-hazard pictograms apply at high severity.

This compound is toxic if swallowed, in contact with skin, or inhaled, and is suspected of causing cancer, with toxic effects that can be delayed well beyond the time of exposure. It is supplied only to buyers with verified closed-system handling infrastructure, full-face supplied-air respiratory protection, totally encapsulating chemical-resistant suits and dedicated emergency-response capability; open handling of this material is never acceptable. Any suspected exposure is a medical emergency requiring immediate professional care. The complete MSDS issued with every shipment must be read in full, and Chelora Chemicals requires documented proof of appropriate handling capability before supplying this product.

07 / STORAGE & SHELF LIFE

Keeping it on spec between delivery and use

General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.

Storage ConditionDedicated, scrubbed, moisture-free facility
ContainerSealed, corrosion-resistant drums / ISO tank
Typical Shelf Life12 months, sealed, dry, cool
Keep Away FromMoisture, strong bases, amines
Beyond Shelf LifeProfessional re-assessment required before any use

Store only in a dedicated, scrubbed, moisture-free facility designed specifically for high-hazard reactive chemicals, in sealed, corrosion-resistant original packaging, away from moisture, strong bases and amine-containing materials, with continuous vapour monitoring and emergency containment in place. This material must never be stored, handled or transferred outside a facility with documented closed-system capability. If a batch is held past its retest date, professional re-assessment is required before any further use.

08 / PACKING & EXPORT

How it ships from Indonesia

Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.

Standard PackingSpecialised corrosion-resistant drums
Bulk PackingDedicated ISO tank, by arrangement only
Min. OrderBy arrangement, verified buyers only
Lead Time3 – 5 weeks
Export TermsFOB · CFR · CIF (restricted logistics)
09 / QUALITY & DOCUMENTATION

What travels with every batch

Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Diethyl Sulfate leaves with a documented, checkable paper trail.

Doc 01

Certificate of Analysis

Batch-wise assay (by titration/GC), colour and relevant physical constants, issued against the agreed specification so your QC team can check it, not just file it.

Doc 02

Safety Data Sheet

GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade of Diethyl Sulfate shipped.

Doc 03

Technical Data Sheet

Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.

Doc 04

Certificate of Origin

Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.

Doc 05

Dangerous Goods Declaration

UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.

Doc 06

Third-Party Inspection

Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.

10 / FAQ

Frequently asked questions

What buyers most often ask our sales desk about this grade.

01What is Diethyl Sulfate used for?+
As an industrial ethylating agent in closed-system dye, pharmaceutical and fine-chemical synthesis, used exclusively by facilities with verified containment and safety infrastructure.
02What is the CAS number of Diethyl Sulfate?+
Its CAS Registry Number is 64-67-5, with molecular formula (C₂H₅)₂SO₄ and a molar mass of 154.19 g/mol.
03How is Diethyl Sulfate made?+
By reacting ethanol with sulfur trioxide (or an equivalent sulfating agent) under closed-system, tightly controlled conditions in dedicated plant with integrated scrubbing.
04What verification does Chelora Chemicals require before supplying this material?+
We require documented proof of closed-system handling infrastructure, appropriate regulatory authorisation and dedicated emergency-response capability before any shipment of Diethyl Sulfate is arranged.
05How does Diethyl Sulfate differ from Dimethyl Sulfate?+
Diethyl Sulfate transfers an ethyl group rather than a methyl group, and is generally somewhat less reactive given the larger, more sterically hindered ethyl group, but both are high-hazard alkylating agents requiring the same closed-system handling discipline.
06Is Diethyl Sulfate hazardous?+
Yes, significantly. It is toxic if swallowed, in contact with skin, or inhaled, and is suspected of causing cancer. It must never be handled outside a fully enclosed, scrubbed system by personnel with the specialised training, respiratory protection and emergency-response capability detailed in the MSDS.
07What packing options are available?+
Packing uses specialised corrosion-resistant drums, with dedicated ISO tank shipment arranged only for verified buyers with the required receiving infrastructure.
08How long does delivery take?+
Typical lead time is three to five weeks including verification, specialised logistics arrangement and transit. A firm date is confirmed only after buyer verification is complete.
09Can I get a sample before placing a bulk order?+
Sample provision for this material is assessed case by case and only after buyer verification is complete — contact our desk to discuss what is practical and permissible for your facility.
10Do you supply Dimethyl Sulfate as well?+
Yes, we also supply Dimethyl Sulfate, the related methylating agent, subject to the same strict handling verification requirements, along with Methanol and Caustic Soda.
Request This Grade

Need Diethyl Sulfate on spec, on time?

Send us your required purity, quantity, packing preference and destination port. Our desk quotes most enquiries within one working day.