Esters Available — Bulk Only

Diethyl Fumarate (Fumaric Acid Diethyl Ester)

CAS 623-91-6 · Formula C8H12O4 · MW 172.18 g/mol

The trans-configured fumarate diester, valued as a reactive comonomer and synthesis intermediate. The unsaturated diester is used as a reactive comonomer and as an intermediate in organic and polymer synthesis.

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HS Code
2917.19
At a Glance
Material Family
Esters
Record Type
Pure compound
Primary Role
Crosslinking / Curing · Synthesis Intermediate
Functional Roles
Crosslinking / Curing Synthesis Intermediate
Industries Served
Coatings & Construction Plastics & Polymers
Applications & Use Cases
  • ▸ Reactive comonomer: Copolymerizes into unsaturated polymer systems.
  • ▸ Synthesis intermediate: Building block for organic and polymer chemistry.
  • ▸ Addition chemistry: Electron-poor double bond for functionalization.
Physical Properties
Physical Description
Colorless liquid
Appearance
White crystal or in liquid form
Boiling Point
214 °C
Melting Point
0.8 °C
Flash Point
104 °C Closed Cup
Solubility
Insoluble in water; soluble in acetone and choloform
Density
1.0452 g/cu cm at 20 °C
Vapor Density
5.93 (Air = 1)
Vapor Pressure
Vapor pressure: 1 mm Hg at 53.2 °C
Autoignition Temperature
104 °C (104 °C)
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2917 . 19
Chapter 29
Organic chemicals
Heading 29.17
Internationally harmonized (WCO HS)
Subheading 2917.19
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
623-91-6
Molecular Formula
C8H12O4
Molecular Weight
172.18 g/mol
IUPAC Name
diethyl (E)-but-2-enedioate
PubChem CID
638144
InChI Key
IEPRKVQEAMIZSS-AATRIKPKSA-N
Synonyms & Trade Names
Diethyl fumarate Fumaric acid, diethyl ester 2-Butenedioic acid (E)-, diethyl ester 2-Butenedioic acid (2E)-, diethyl ester 2-Butenedioic acid, diethyl ester, (E)- Diethylester kyseliny fumarove trans-2-Butenedioic acid diethyl ester 1,4-diethyl (2Z)-but-2-enedioate Anti-Psoriaticum diethyl (E)-but-2-enedioate Fumaric Acid Diethyl Ester diethyl (2E)-but-2-enedioate 1,4-diethyl (2E)-but-2-enedioate (E)-but-2-enedioic acid diethyl ester (2E)-2-Butenedioic acid diethyl ester
Full Description

Diethyl fumarate (CAS 623-91-6) is the diethyl ester of fumaric acid, the trans isomer of diethyl maleate. The unsaturated diester is used as a reactive comonomer and as an intermediate in organic and polymer synthesis. Its electron-poor double bond participates in addition and copolymerization reactions.

Frequently Asked Questions

What is diethyl fumarate used for?

Diethyl fumarate (CAS 623-91-6) is the diethyl ester of fumaric acid, used as a reactive comonomer in unsaturated polymer systems and as an intermediate in organic and polymer synthesis. Its electron-poor double bond participates in addition and copolymerization reactions, making it a building block for functionalized materials.

What is fumarate made of?

Diethyl fumarate is the diethyl ester of fumaric acid, a four-carbon trans-unsaturated dicarboxylic acid, esterified with two ethanol groups (C8H12O4). It is the trans isomer corresponding to diethyl maleate (the cis isomer).

Is diethyl fumarate the same as diethyl maleate?

No. Diethyl fumarate and diethyl maleate share the formula C8H12O4 but are geometric isomers — fumarate is the trans isomer and maleate is the cis isomer across the double bond. The difference in geometry changes their reactivity and physical properties in copolymerization.

What is the CAS number for diethyl fumarate?

Diethyl fumarate's CAS number is 623-91-6, formula C8H12O4, classified under HS 2917.19 (acyclic polycarboxylic acid esters). RawSource provides a Certificate of Analysis and SDS with each bulk shipment.

What is the cost of bulk diethyl fumarate?

Bulk diethyl fumarate pricing varies with volume, packaging, and freight. RawSource supplies it in drums and totes to polymer and specialty-chemical manufacturers; request a bulk quote with your volume and ship-to for current pricing.

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Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.

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