Esters Available — Bulk Only

Diethyl Maleate (DEM)

CAS 141-05-9 · Formula C8H12O4 · MW 172.18 g/mol

An unsaturated diester whose activated double bond drives Michael additions and copolymerizations. Its activated carbon-carbon double bond makes it a Michael acceptor and a comonomer for copolymers with styrene and vinyl chloride.

Safety Data Sheet
HS Code
2917.19
At a Glance
Material Family
Esters
Record Type
Pure compound
Primary Role
Crosslinking / Curing · Synthesis Intermediate
Applications & Use Cases
  • Comonomer: Copolymerizes with styrene and vinyl chloride to modify resin properties.
  • Reactive intermediate: Michael acceptor for addition chemistry and downstream synthesis.
  • Polymer modifier: Chemical modifier in resin and specialty-chemical production.
Physical Properties
Physical Description
Water-white liquid; Colorless clear liquid
Boiling Point
218.00 °C. @ 760.00 mm Hg
Solubility
1.40E+04 mg/L @ 30 °C (exp)
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.

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
141-05-9
Molecular Formula
C8H12O4
Molecular Weight
172.18 g/mol
IUPAC Name
diethyl (Z)-but-2-enedioate
PubChem CID
InChI Key
IEPRKVQEAMIZSS-WAYWQWQTSA-N
Synonyms & Trade Names
DIETHYL MALEATE Diethylmaleate Maleic acid, diethyl ester 2-Butenedioic acid (2Z)-, diethyl ester Diethylester kyseliny maleinove STAFLEX DEM diethyl maleic acid diester Maleic acid diethyl ester diethyl (Z)-but-2-enedioate Diethyl (Z)-2-butenedioate 2-Butenedioic acid (Z)-, diethyl ester diethyl (2Z)-but-2-enedioate 2-Butenedioic acid (2Z)-, 1,4-diethyl ester 2-Butenedioic acid, diethyl ester, (Z)- 2-Butenedioic acid, diethyl ester, (2Z)- Diethyl (2E)-2-butenedioate
Full Description

Diethyl maleate (DEM, CAS 141-05-9) is the diethyl ester of maleic acid, an unsaturated difunctional ester used as a reactive intermediate in organic synthesis. Its activated carbon-carbon double bond makes it a Michael acceptor and a comonomer for copolymers with styrene and vinyl chloride. It also serves as a chemical modifier in polymer and specialty-chemical manufacture.

Frequently Asked Questions

What is diethyl maleate used for?

Diethyl maleate (DEM, CAS 141-05-9) is an unsaturated difunctional ester used as a reactive intermediate in organic synthesis. Its activated double bond makes it a Michael acceptor for addition chemistry and a comonomer that copolymerizes with styrene and vinyl chloride to modify resin properties. It also serves as a chemical modifier in polymer and specialty-chemical manufacture.

What is the difference between diethyl maleate and dimethyl maleate?

Both are diesters of maleic acid; diethyl maleate uses two ethyl groups (C8H12O4) while dimethyl maleate uses two methyl groups, giving it a lower molecular weight and different boiling point. Both act as Michael acceptors and reactive comonomers, with the ester choice affecting solubility and reactivity in a given system.

Is diethyl maleate the same as diethyl fumarate?

No. They are geometric isomers sharing formula C8H12O4 — diethyl maleate is the cis isomer of the double bond and diethyl fumarate is the trans isomer. The geometry affects their reactivity and physical properties in synthesis and copolymerization.

What is the CAS number for diethyl maleate?

Diethyl maleate's CAS number is 141-05-9, formula C8H12O4, classified under HS 2917.19. RawSource supplies it in drums and totes with a Certificate of Analysis and SDS per shipment.

What is the cost of bulk diethyl maleate?

Bulk DEM pricing depends on volume, packaging, and freight to your location. RawSource quotes against current supply; submit a bulk quote request with your target volume and ship-to for firm pricing.

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.