Diethyl Malonate
1. Basic Identification
CAS No.: 617-89-0
Chemical Name: Diethyl Malonate
IUPAC Name: Diethyl propanedioate
Abbreviation: DEM
Synonyms: Malonic acid diethyl ester, Ethyl malonate
EINECS No.: 210-535-5
Molecular Formula: C₇H₁₂O₄
Structural Formula: CH₂(COOCH₂CH₃)₂
Molecular Weight: 160.17
SMILES: CCOC(=O)CC(=O)OCC
UN Number: UN 3082
HS Code: 2917190090
Hazard Classification: Class 9 Environmentally Hazardous Substance, Packing Group III
Chemical Category: Aliphatic diester containing active methylene group, universal core intermediate for organic synthesis
2. Physical and Chemical Properties
Appearance
Colorless transparent oily liquid with mild sweet fruity ester odor; stable without turbidity or precipitate under dry sealed storage.
Physical Constants
| Parameter | Value | Remarks |
| Melting Point | -49 ℃ | Remains liquid under normal warehouse temperature |
| Boiling Point | 198–199 ℃ (760 mmHg) | High boiling point with low volatility |
| Density (20 ℃) | 1.055–1.058 g/mL | Slightly heavier than water |
| Refractive Index n₂₀/D | 1.413–1.415 | Standard detection index |
| Closed Cup Flash Point | 93 ℃ | Combustible liquid with low fire risk |
| Autoignition Temperature | 440 ℃ |
|
| Explosion Limit in Air | 1.2 ~ 8.0 vol% |
|
| Vapor Pressure (20 ℃) | 0.04 mmHg | Hardly volatile at room temperature |
| Water Solubility | 2.0 g/100 mL (25 ℃) | Slightly soluble in cold water |
| Organic Solubility | Fully miscible with ethanol, methanol, acetone, ethyl acetate, toluene, xylene, chloroform and DMF; slightly soluble in aliphatic alkane oils |
|
Core Chemical Characteristics
- Active methylene group (-CH₂-) is the key structural feature. Two adjacent carbonyl groups produce strong electron-withdrawing effect, making the central hydrogen weakly acidic (pKa≈13). It can form enolate anions under weak bases such as sodium ethoxide and triethylamine, supporting alkylation, Knoevenagel condensation and Michael addition reactions, which is the core raw material for classic malonic ester synthesis.
- Alkylation Reaction: Reacts with alkyl halides to generate mono- and di-substituted malonate diesters. Substituted aliphatic carboxylic acids can be obtained after alkaline hydrolysis and thermal decarboxylation, widely used for the synthesis of drug molecular fragments.
- Knoevenagel Condensation: Condenses with aldehydes and ketones to produce α,β-unsaturated diesters, which are raw materials for coumarin fluorescent whitening agents and nitrogen-containing heterocyclic APIs.
- Ester Hydrolysis:
- Hydrolysis under alkaline heating produces disodium malonate; malonic acid can be obtained after acidification.
- Decarboxylation occurs under strong acid and high temperature to generate acetic acid derivatives.
- Transesterification: Under acid or base catalysis, ethoxy groups can exchange with other alcohols to produce dimethyl malonate, dibutyl malonate and other malonate ester derivatives.
- Thermal Stability: Stable below 180 ℃; slow decomposition occurs above boiling point to release ethanol and carbon dioxide.
- Incompatible Substances: Strong concentrated alkalis, strong oxidants and strong reducing agents.
3. Export Industrial Quality Specifications
Premium Industrial Grade (GC ≥99.0%, mainstream export grade)
| Test Item | Standard Spec | Test Method |
| Diethyl Malonate Assay | ≥99.0 % | GC-FID Gas Chromatography |
| Monoethyl Malonate Impurity | ≤0.30 % | GC |
| Residual Ethanol | ≤0.10 % | GC |
| Moisture Content | ≤0.10 % | Karl Fischer Titration |
| Free Acid (Calculated as Malonic Acid) | ≤0.05 % | Potentiometric Titration |
| Color (APHA/Hazen) | ≤20 | Platinum-Cobalt Colorimetry |
| Distillation Range (197–200 ℃) | ≥95 vol% | Atmospheric Distillation |
| Heavy Metals (Pb, As) | ≤10 ppm | Atomic Absorption Spectroscopy (AAS) |
| Appearance | Colorless clear liquid without turbidity or sediment | Visual Inspection |
High-Purity Pharmaceutical Grade (GC ≥99.5%)
Single ester impurity ≤0.05%, moisture <50 ppm, heavy metal <1 ppm, nitrogen-sealed anhydrous packaging for chiral APIs and peptide intermediate synthesis.
4. Main Industrial Applications
4.1 Pharmaceutical & Peptide Synthesis (High-Value Core Field)
- Key building block for anti-inflammatory drugs, antibiotics, cardiovascular drugs and anti-tumor heterocyclic APIs.
- Synthesize pyridine, pyrimidine, quinoline nitrogen-containing heterocyclic drug skeletons via Knoevenagel condensation.
- Modify amino acid side chains in solid-phase peptide synthesis to prepare branched carboxylic acid fragments.
- Raw material for the production of Vitamin B1 and Vitamin B6.
4.2 Agrochemical Intermediates
- Starting material for herbicides, fungicides and insecticides; substituted carboxylic acid pesticide active ingredients are produced through alkylation and decarboxylation.
- Precursor of plant growth regulators and chelating auxiliaries for pesticide formulations.
4.3 Fluorescent Brightener & Dye Industry
- Condenses with aromatic aldehydes to produce coumarin fluorescent whitening agents for textiles, paper and plastic brightening treatment.
- Intermediate for azo disperse dyes and organic fluorescent pigments.
4.4 Coatings, Plastics & Fine Chemicals
- Crosslinking monomer for waterborne baking coatings, improving coating hardness, gloss and weather resistance.
- Polyurethane chain extender and low-temperature plasticizer for PVC resin.
- Raw material for synthesizing metal chelating agents and circulating water scale inhibitors.
4.5 Laboratory Analytical Reagent
Standard substrate for teaching and research on malonic ester alkylation, condensation and Michael addition reaction mechanisms.
5. Safety, Packaging, Storage & Transportation Regulations
GHS Hazard Classification
Signal Word: Warning
Hazard Statements:
H315 Causes skin irritation
H318 Causes serious eye damage
H413 May cause long-lasting harmful effects to aquatic life
Export Standard Packaging
- Bulk industrial cargo: 200L anti-rust lined steel drum with PTFE leak-proof gaskets
- Medium batch goods: 25L plastic-lined iron drum
- High-purity pharmaceutical grade: Aluminum foil inner bag + light-proof iron drum, nitrogen sealed
- Laboratory trial package: 1L / 5L brown anti-leak glass bottle
Storage Requirements
- Store in a cool, dry and well-ventilated general chemical warehouse with ambient temperature ≤30 ℃. All drums must be tightly sealed to prevent solvent volatilization and moisture absorption.
- Store separately from strong alkalis, oxidants, food raw materials and feed.
- Equip the operation area with exhaust ventilation, nitrile chemical resistant gloves, impact-resistant safety goggles and emergency eyewash station.
- Shelf life: 12 months under original sealed packaging; re-test purity after expiration date.
Transportation Rules
UN 3082, Class 9 environmentally hazardous dangerous goods, Packing Group III
- Keep packages waterproof and shaded during transit; avoid high-temperature stacking and long-term direct sunlight exposure.
- Prohibit mixed loading with alkaline chemicals, edible raw materials and strong oxidants in the same container.
- Complete export documents available: COA, MSDS, TDS, marine dangerous goods declaration, REACH compliance report.
6. E-commerce Listing Text (Directly Used for Alibaba / Echemi)
Product Title
Diethyl Malonate Diethyl Propanedioate DEM CAS 617-89-0 99% Colorless Liquid Active Methylene Intermediate for Pharmaceutical API Peptide Coumarin Fluorescent Brightener Agrochemical
Short Description
Diethyl Malonate (C₇H₁₂O₄, CAS 617-89-0) ≥99% high-boiling ester liquid with active methylene group. It is a classic raw material for malonic ester synthesis, widely used in the production of pharmaceutical heterocyclic APIs, solid-phase peptide fragments, textile coumarin fluorescent whitening agents and agricultural fungicide intermediates. Full set of export documents including COA, MSDS and TDS can be provided for global bulk shipment.
Full Description
Diethyl Malonate (DEM, Diethyl propanedioate, CAS 617-89-0) is an essential diester fine chemical with active methylene group, supplied as colorless transparent liquid with GC purity ≥99.0%. Its weakly acidic central methylene can participate in alkylation, Knoevenagel condensation and Michael addition reactions, making it an irreplaceable core building block in multi-step organic synthesis.
Main downstream application sectors include high-end pharmaceutical raw materials for anti-inflammatory, cardiovascular and heterocyclic APIs; coumarin fluorescent whitening agents for textile and paper finishing; agricultural herbicide and fungicide intermediates; crosslinkers for water-based coatings and standard laboratory synthesis reagents. We also supply 99.5% ultra-high purity pharmaceutical grade with ultra-low free acid and moisture for fine peptide and chiral drug manufacturing.
Products are packed in lined steel drums for full-container sea shipment. Classified as UN3082 Class 9 environmentally hazardous goods, we provide complete customs clearance certification documents to support global sea and land transportation with stable long-term supply capacity.
7. Printable Export COA Template
CERTIFICATE OF ANALYSIS
Product Name: Diethyl Malonate (DEM)
CAS No.: 617-89-0
Grade: Export Premium Industrial Grade
Batch No.: ____________
Net Weight: 200kg/drum
Manufacture Date: ____________
| Test Item | Standard Spec | Test Result | Test Method |
| Diethyl Malonate Assay | ≥99.0 % |
| GC Gas Chromatography |
| Monoethyl Malonate Impurity | ≤0.30 % |
| GC |
| Residual Ethanol | ≤0.10 % |
| GC |
| Moisture Content | ≤0.10 % |
| Karl Fischer Titration |
| Free Acid (as Malonic Acid) | ≤0.05 % |
| Acid-Base Titration |
| Color (APHA) | ≤20 |
| Platinum-Cobalt Colorimetry |
| Appearance | Colorless clear liquid without sediment | Visual Inspection |
|
Conclusion: This batch complies with export premium industrial standard of Diethyl Malonate.
Inspector Signature: ____________
Testing Date: ____________
TDS
