Isopropyl ether
[CAS# 108-20-3]

Identification

• Classification: Organic raw materials >> Ether compounds and their derivatives >> Ether, ether alcohol
• Name: Isopropyl ether
• Synonyms: 2-Isopropoxypropane; Diisopropylether; DIPE; 2,2'-Oxybispropane
• Molecular Formula: C₆H₁₄O
• Molecular Weight: 102.17
• CAS Registry Number: 108-20-3
• EC Number: 203-560-6
• SMILES: CC(C)OC(C)C

Properties

• Density: 0.725 g/mL (Expl.)
• Melting point: -85 °C (Expl.)
• Boiling point: 68-69 °C (Expl.)
• Refractive index: 1.367 (Expl.)
• Flash point: -29 °C (Expl.)
• Water solubility: 9 g/L (20 °C)

Safety Data

• Hazard Symbols: GHS02;GHS07 Danger
• Risk Statements: H225-H336-H412
• Safety Statements: P210-P233-P240-P241-P242-P243-P261-P271-P273-P280-P303+P361+P353-P304+P340-P319-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Specific target organ toxicity - single exposure	STOT SE	3	H336
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Reproductive toxicity	Repr.	2	H361
Specific target organ toxicity - single exposure	STOT SE	2	H371

• Transport Information: UN 1159

Discovery and Applications

Isopropyl ether is an organic compound classified as a symmetrical ether with the chemical formula (C3H7)2O. It is a colorless, highly volatile liquid with a characteristic ether-like odor. Due to its low polarity and ability to dissolve a wide range of organic substances, isopropyl ether has found applications in industrial processes, chemical synthesis, and laboratory research. Its discovery and widespread use have contributed significantly to the development of organic chemistry and industrial solvent technology.

The synthesis of isopropyl ether dates back to the early advancements in ether chemistry during the 19th century. It is commonly produced through the acid-catalyzed dehydration of isopropanol, a method similar to that used in the production of diethyl ether. This reaction involves the removal of a water molecule from two isopropanol molecules in the presence of a strong acid such as sulfuric acid or phosphoric acid. The resulting product is a highly flammable and volatile ether that requires careful handling due to its low flash point and potential for explosive peroxides formation upon prolonged exposure to air and light.

One of the primary applications of isopropyl ether is as a solvent in industrial and chemical processes. Its non-polar nature makes it particularly effective for dissolving fats, oils, resins, and certain polymers. It is commonly used in the extraction and purification of pharmaceuticals, where selective solubility properties allow for the separation of desired compounds from reaction mixtures. Additionally, isopropyl ether has been employed as a reaction medium in organic synthesis, particularly in Grignard reactions and other anhydrous conditions where water-sensitive reagents are involved.

In the petroleum and automotive industries, isopropyl ether has been explored as a fuel additive and antiknock agent. Its volatility and combustion characteristics can enhance the performance of gasoline blends, improving engine efficiency and reducing knocking tendencies. However, due to its tendency to form peroxides over time, its use in large-scale fuel applications is limited, requiring stabilizers and careful storage conditions to prevent hazardous decomposition.

Isopropyl ether has also been used as an alternative solvent in cleaning and degreasing applications, particularly in electronics and precision instrument manufacturing. Its ability to dissolve non-polar contaminants while evaporating quickly without leaving residues makes it suitable for applications where water-based cleaning agents are not effective. Additionally, it has been employed in laboratory settings as a solvent for extractions and recrystallization processes.

Despite its useful properties, isopropyl ether poses certain safety and environmental concerns. It is highly flammable, with vapors that can form explosive mixtures with air. Over time, exposure to oxygen can lead to the formation of peroxides, which are potentially explosive under certain conditions. Proper storage in tightly sealed containers with inhibitors such as butylated hydroxytoluene (BHT) is necessary to minimize these risks. Furthermore, its volatility contributes to air pollution, and regulations have been established to control emissions in industrial settings.

Research continues to explore safer and more stable alternatives to isopropyl ether, particularly in applications where solvent stability and environmental impact are critical factors. Advances in green chemistry have led to the development of less hazardous ethers and sustainable solvent alternatives that maintain similar solubility properties while reducing safety risks.

Isopropyl ether remains an important compound in chemical and industrial applications due to its versatility as a solvent and reaction medium. While its use has declined in some areas due to safety concerns, it continues to be valuable in specialized processes requiring non-polar solvents with high volatility and low water solubility.

References

2005. Enhancement of enzyme activity and enantioselectivity by cyclopentyl methyl ether in the transesterification catalyzed by Pseudomonas cepacia lipase co-lyophilized with cyclodextrins. Biotechnology Letters.
DOI: 10.1007/s10529-005-1527-1

1996. Isolation and selection of biosurfactant-producing bacteria. World Journal of Microbiology and Biotechnology.
DOI: 10.1007/bf00327807

2008. A field-adapted sampling and HPLC quantification method for lumefantrine and its desbutyl metabolite in whole blood spotted on filter paper. Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences.
DOI: 10.1016/j.jchromb.2008.11.002