Cyclopropyl acetylene
[CAS# 6746-94-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Alkyne
• Name: Cyclopropyl acetylene
• Synonyms: Cyclopropylacetylene
• Molecular Formula: C₅H₆
• Molecular Weight: 66.10
• CAS Registry Number: 6746-94-7
• EC Number: 425-430-1
• SMILES: C#CC1CC1

Properties

• Density: 0.7801 g/mL (Expl.)
• Index of Refraction: 1.448 (Expl.)
• Boiling point: 79-80 °C (Expl.)
• Flash point: -17 °C (Expl.)

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07 Danger
• Risk Statements: H225-H314-H318-H412
• Safety Statements: P210-P233-P240-P241-P242-P243-P260-P264-P264+P265-P273-P280-P301+P330+P331-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P317-P321-P363-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Flammable liquids	Flam. Liq.	2	H225
Serious eye damage	Eye Dam.	1	H318
Serious eye damage	Eye Dam.	1	H319

Discovery and Applications

Cyclopropyl acetylene is an organic compound with the chemical formula C5H6. It consists of a cyclopropyl group, a three-membered ring structure, attached to an acetylene group, a carbon-carbon triple bond. This compound is an unsaturated hydrocarbon with a distinct structure that makes it an interesting intermediate in organic synthesis. The compound's synthesis and reactivity have been of significant interest in the fields of synthetic chemistry and materials science.

The discovery of cyclopropyl acetylene dates back to the mid-20th century, as chemists explored ways to modify alkynes and cyclopropyl derivatives to develop new materials and reactions. The compound was initially synthesized as a potential reagent for use in various chemical reactions. Its unique structure, combining the strained three-membered cyclopropyl ring with the highly reactive triple bond, made it an intriguing candidate for study in organic synthesis.

Cyclopropyl acetylene is highly reactive due to the strain in the cyclopropyl ring and the electron-rich nature of the acetylene group. This reactivity makes it useful in a variety of chemical reactions. One important application is in the synthesis of other organic compounds, including complex molecules used in pharmaceuticals, agrochemicals, and materials science. The strain in the cyclopropyl ring often results in ring-opening reactions, which can be used to generate new chemical entities with diverse functional groups.

One of the key applications of cyclopropyl acetylene is in the synthesis of complex polycyclic compounds. The strained nature of the cyclopropyl ring facilitates its participation in reactions that lead to the formation of larger, more complex ring systems. These reactions can be useful in the development of novel materials, including those used in the production of polymers and specialty chemicals. The compound's ability to undergo ring-opening reactions is also valuable in the preparation of intermediates for further chemical transformations.

In addition to its role in organic synthesis, cyclopropyl acetylene has been explored for its potential in the field of catalysis. The compound's unique structure allows it to participate in reactions with transition metals, leading to the formation of metal-organic complexes that can serve as catalysts in various chemical processes. These catalytic processes are important in industries such as petrochemicals, environmental chemistry, and pharmaceuticals, where efficient and selective reactions are required.

Cyclopropyl acetylene has also been studied for its potential biological activity. Although it is not widely used as a drug itself, its derivatives have been explored for their pharmacological properties. Some studies have suggested that compounds derived from cyclopropyl acetylene could have antimicrobial or anticancer activity. Further research in medicinal chemistry is ongoing to fully understand the therapeutic potential of these derivatives.

The compound's application in materials science is also noteworthy. Its reactive nature and ability to participate in polymerization reactions make cyclopropyl acetylene a valuable building block for the development of new materials with tailored properties. These materials could find applications in areas such as coatings, adhesives, and electronics, where high-performance materials are required.

Despite its versatility, cyclopropyl acetylene is also known for its volatility and sensitivity to conditions such as light, heat, and moisture. As with many organic compounds, it must be handled carefully in the laboratory to avoid unwanted reactions. Proper storage and safety precautions are essential when working with this compound to ensure safe handling and use.

In conclusion, cyclopropyl acetylene is an important compound in the field of organic chemistry, with a wide range of applications in synthesis, catalysis, and materials science. Its unique structure, which combines the strained cyclopropyl ring with the reactive acetylene group, makes it a valuable tool in the development of new chemical reactions and the synthesis of complex molecules. Ongoing research into its properties and applications will likely continue to reveal new uses for this versatile compound.

References

2024. Alkynyl cyclopropanes in organic synthesis. Russian Chemical Bulletin, 73(1).
DOI: 10.1007/s11172-024-4121-1

2021. Methods for the synthesis of functionalized alkynylcyclopropanes. Russian Chemical Bulletin, 70(11).
DOI: 10.1007/s11172-021-3318-9

1978. Synthesis and conversions of cyclopropylacetylenes. Bulletin of the Academy of Sciences of the USSR, Division of chemical science, 27(6).
DOI: 10.1007/bf00923368