Cyclopentyl Methyl Ether (CPME)
1. Basic Identification
Chemical Name: Cyclopentyl methyl ether
Abbreviation: CPME
Synonyms: Methoxycyclopentane, Cyclopentylmethylether
EINECS No.: 218-032-2
MDL No.: MFCD00010647
Molecular Formula: \(\boldsymbol{C_6H_{12}O}\)
Molecular Weight: 100.16
SMILES: COC1CCCC1
UN Number: UN 1993
HS Code: 2909199090
Hazard Classification: Class 3 Flammable Liquid, Packing Group II
Chemical Category: Cyclic ether, high-boiling green alternative solvent to THF / MTBE / diethyl ether, reaction & extraction solvent for pharma fine synthesis
2. Physical & Chemical Properties
Appearance
Colorless transparent low-viscosity liquid, mild ethereal odor; much lower peroxide formation tendency than tetrahydrofuran and diethyl ether.
Physical Constants
| Parameter | Standard Value | Remarks |
| Melting Point | -140 ℃ | Extremely low freezing point, stable at low temperature reaction conditions |
| Boiling Point | 106–107 ℃ (760 mmHg) | Medium high boiling point, easy to recover by vacuum distillation |
| Density (20 ℃) | 0.860–0.863 g/mL | Lighter than water, floats on water |
| Refractive Index \(n_{20/D}\) | 1.405–1.407 | Core purity testing index |
| Closed Cup Flash Point | -1 ℃ | Highly flammable liquid |
| Autoignition Temperature | 270 ℃ |
|
| Explosion Limit in Air (V/V) | 1.1% ~ 9.9% | Flammable range exists in confined space |
| Vapor Pressure (20 ℃) | 4.2 kPa | Vapor heavier than air, accumulates in low zones |
| Water Solubility | 1.1 g/100 mL | Limited miscibility with water, easy liquid-liquid separation |
| Organic Miscibility | Fully miscible with alcohols, ketones, esters, aromatic hydrocarbons, aliphatic solvents |
|
Core Chemical Characteristics
- Low peroxide generation
Cyclopentyl ring structure greatly slows auto-oxidation under air exposure, safer long-term storage than THF, minimal peroxide risk without frequent distillation. - Weakly polar inert ether solvent
Stable against strong bases, Grignard reagents, organolithium reagents; compatible with low-temperature metal organic synthesis. - Azeotropic separation advantage
Forms azeotrope with water (azeotrope boiling ~83 ℃), simple dehydration separation after extraction; low water solubility reduces solvent loss into aqueous layer. - Hydrolysis resistance
Stable under neutral / weak acid conditions; only hydrolyzes under strong concentrated acid heating to cyclopentanol and methanol. - Incompatible materials: Strong oxidants, hot concentrated mineral acids, liquid chlorine, peroxide initiators.
3. Export Industrial Quality Specifications
Premium Synthetic Grade ≥99.5% (Mainstream Export)
| Test Item | Standard Spec | Test Method |
| CPME Assay | ≥99.5 % | GC-FID Gas Chromatography |
| Cyclopentanol Impurity | ≤0.10 % | GC |
| Methanol Residual | ≤0.05 % | GC |
| Moisture Content | ≤0.03 % | Karl Fischer Titration |
| Peroxide Value | ≤5 ppm | Iodometric titration |
| Color (APHA) | ≤10 | Platinum-Cobalt Colorimetry |
| Distillate 105–108 ℃ | ≥95 vol% | Atmospheric distillation test |
| Appearance | Colorless clear liquid without turbidity or sediment | Visual Inspection |
Anhydrous Ultra-Dry Grade ≥99.9%
Moisture <10 ppm, nitrogen sealed packaging, specially for organometallic / peptide / chiral API low-temperature reactions.
4. Main Industrial Applications
4.1 Pharmaceutical Fine Chemical Synthesis (Core High-Value Field)
- Replacement solvent for THF / diethyl ether in Grignard, organolithium, low-temperature coupling reactions; low peroxide risk improves production safety.
- Extraction solvent for chiral intermediates, APIs and natural plant alkaloids; easy recovery via distillation, low solvent residue.
- Crystallization medium for high-purity drug substance purification, obtains uniform crystal particles with high filtration efficiency.
- Reaction solvent for cyclopentyl series intermediates synthesis (cyclopentene, cyclopentanol, cyclopentyl halide).
4.2 Polymer & Coating Industry
- Slow-evaporating high-solubility solvent for high-end polyurethane, acrylic resin coatings and printing inks, excellent leveling performance.
- Diluent for electronic insulating varnish, reduces surface pinholes and film shrinkage.
4.3 Separation & Extraction Industry
- Industrial liquid-liquid extraction agent for wastewater organic matter recovery, rare metal separation.
- Azeotropic dehydrating agent for alcohol / ester system dehydration instead of benzene / toluene toxic solvents.
4.4 Laboratory Universal Green Solvent
Safer alternative to ether and THF for organic chemistry labs; suitable for reduction, alkylation, condensation and asymmetric synthesis reactions.
5. Toxicology, Health Hazards & First Aid
Toxicity Profile
- Acute Oral LD50 (Rat) >2000 mg/kg (Category 4, harmful if swallowed)
- Dermal hazard: Mild skin degreasing effect; long-term contact causes dry skin and slight itching
- Inhalation hazard: High concentration vapor induces dizziness, lethargy and mild respiratory tract irritation
- Eye hazard: Slight stinging and conjunctival redness after splashing
- Environmental hazard: Moderately harmful to aquatic life, readily biodegradable compared to other ethers
Exposure Symptoms
- Inhalation of vapor: Throat mild irritation, headache, fatigue, drowsiness under high concentration
- Skin contact: Dry tight skin, slight erythema after prolonged continuous exposure
- Eye splash: Temporary stinging, blurred vision, mild conjunctival congestion
- Oral ingestion: Mild stomach distension, nausea without severe corrosion injury
Complete First-Aid Procedures
- Inhalation: Move victim to fresh upwind air, rest and observe; supply oxygen if breathing difficulty occurs
- Skin Contact: Remove contaminated clothes immediately, rinse skin with plenty of running clean water for ≥15 minutes
- Eye Contact: Force open eyelids, flush eyes with clean cold water continuously for more than 15 minutes
- Oral Intake: DO NOT induce vomiting; drink large amounts of clean water for dilution and seek medical treatment if discomfort persists
6. Storage, Handling & Incompatibility Rules
Mandatory Storage Conditions
- Warehouse classification: Dedicated Class 3 flammable liquid explosion-proof warehouse, separated from oxidants, concentrated acids, food and feed materials
- Temperature control: Ambient storage temperature ≤25 ℃, light-shaded to slow peroxide generation
- Sealing requirement: Steel drums sealed with PTFE gaskets; nitrogen blanketing recommended for long-term stock, warehouse equipped with flammable vapor alarm
- Static control: All transfer pipelines and pallets static grounded; only non-sparking copper tools allowed for loading/unloading
- Shelf life: 12 months under original sealed packaging; peroxide test required once opened for long-term use
Strictly Separated Incompatible Materials
Strong oxidants, concentrated sulfuric acid / hydrochloric acid, chlorine gas, organic peroxides, edible raw materials
Safe Operation Specifications
- Operators wear nitrile solvent-resistant gloves, impact safety goggles and anti-static work clothes; activated carbon organic vapor mask required in poorly ventilated closed workshops
- No open flame, smoking or static sparks within 10-meter operation radius
- Small leakage: Absorb with dry inert sand, collect waste into sealed hazardous waste metal barrels; prohibit direct discharge into sewer
- Large leakage: Build sand retaining dikes to contain liquid, ventilate fully to disperse flammable vapor, prevent infiltration into soil and water bodies
7. Export Packaging & Global Transportation Regulations
Standard Export Packaging Modes
- Industrial bulk grade: 200L carbon steel sealed drum with PTFE anti-leak gaskets
- Medium batch goods: 25L plastic-lined iron drum
- Lab anhydrous reagent package: 1L / 5L brown light-proof plastic bottle with outer protective carton
- Large-volume ocean shipment: 20ft stainless steel ISO tank container with static grounding device
UN Transport Compliance Rules
UN 1993, Class 3 Flammable Liquid, Packing Group II
- Road transport: Vehicles fitted with exhaust flame arrestors, dual dry powder & CO₂ fire extinguishers, ventilated cargo compartment
- Ocean shipment: Comply with IMDG flammable liquid dangerous goods standards; affix flammable hazard labels on every drum, stacking height ≤2 layers
- Loading ban: Mixed loading with oxidants, strong acids, edible goods and metal powders in one container is strictly forbidden
Full Export Document Package
- Batch Certificate of Analysis (COA)
- GHS-compliant MSDS / SDS
- Technical Data Sheet (TDS)
- Marine Dangerous Goods Declaration
- REACH Compliance Registration Report
8. GHS Global Hazard Label Statements
Signal Word: Danger
Hazard Statements:
H225 Highly flammable liquid and vapor
H315 Causes skin irritation
H319 Causes serious eye irritation
H336 May cause drowsiness or dizziness
H412 Harmful to aquatic life with long lasting effects
Precautionary Statements:
P210 Keep away from heat, sparks, open flames, hot surfaces – No smoking
P261 Avoid breathing vapor/mist
P280 Wear protective gloves and eye protection
P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes
P403+P235 Store in a well-ventilated place. Keep cool and tightly sealed.
9. Fire Emergency Disposal Plan
Approved Fire Extinguishing Agents
- Primary: Dry chemical powder, carbon dioxide (CO₂)
- Auxiliary: Alcohol-resistant foam fire extinguishing agent
Forbidden Agents
Direct high-pressure water jet (liquid floats on water surface and spreads flammable vapor range to expand fire risk)
Fire Site Operation Steps
- Evacuate all personnel to upwind safe zone, isolate fire area and cut all ignition sources
- Continuously cool surrounding stacked CPME drums with water mist to prevent thermal expansion rupture and vapor leakage
- Collect all fire residual waste liquid and solid as hazardous waste for centralized incineration treatment; prohibit direct discharge into water bodies
10. Printable Export COA Template
CERTIFICATE OF ANALYSIS
Product Name: Cyclopentyl Methyl Ether (CPME)
CAS No.: 2040-95-1
Grade: Export Industrial Synthetic Grade
Batch No.: ____________
Net Weight: 200kg/drum
Manufacture Date: ____________
| Test Item | Standard Spec | Test Result | Test Method |
| CPME Purity | ≥99.5 % |
| GC Gas Chromatography |
| Cyclopentanol Impurity | ≤0.10 % |
| GC |
| Methanol Residual | ≤0.05 % |
| GC |
| Moisture Content | ≤0.03 % |
| Karl Fischer Titration |
| Peroxide Value | ≤5 ppm |
| Iodometric Titration |
| Color (APHA) | ≤10 |
| Platinum-Cobalt Colorimetry |
| Appearance | Colorless clear liquid without turbidity or sediment | Visual Inspection |
|
Conclusion: This batch complies with export industrial standard of Cyclopentyl Methyl Ether (CPME).
Inspector Signature: ____________
Issuance Date: ____________
11. E-commerce Listing Copy (Alibaba / Echemi Direct Use)
Product Title
Cyclopentyl Methyl Ether CPME CAS 2040-95-1 99.5% Green Ether Solvent Safe Substitute for THF Grignard Reaction API Extraction Crystallization Medium Low Peroxide
Short Description
Cyclopentyl methyl ether (C₆H₁₂O, CAS 2040-95-1) ≥99.5% low-peroxide cyclic ether solvent, safer alternative to THF, diethyl ether and MTBE. Widely used for pharmaceutical Grignard/organolithium synthesis, API liquid-liquid extraction and drug recrystallization. Full set of UN1993 Class 3 flammable dangerous goods export documents COA, MSDS and TDS available for global bulk drum shipment.
Full Description
Cyclopentyl methyl ether (abbreviated CPME, CAS 2040-95-1) is an eco-friendly cyclic ether fine chemical, supplied as colorless transparent liquid with GC purity ≥99.5%. Its unique cyclopentyl ring structure drastically inhibits peroxide formation during storage, solving the major safety hazard of traditional ether solvents like THF and diethyl ether. With moderate boiling point, limited water miscibility and excellent solubility for organics, it becomes a mainstream green solvent in high-end fine chemical manufacturing.
Core downstream application sectors: reaction solvent for low-temperature organometallic synthesis (Grignard, organolithium, asymmetric coupling); extraction and recrystallization medium for pharmaceutical APIs, chiral intermediates and natural extracts; high-boiling slow-evaporating diluent for polyurethane and acrylic industrial coatings; laboratory universal organic synthesis solvent replacing toxic ethers. We supply standard industrial synthesis grade and ultra-dry anhydrous special grade for strict water-free production processes.
Packed in sealed anti-rust steel drums for full-container sea freight. Classified UN1993 Class 3 flammable liquid dangerous goods, we provide complete IMDG transport, customs clearance and REACH compliance certificates for stable long-term global supply to pharmaceutical factories, fine chemical labs and coating manufacturers.
