Cyclopropylacetylene

Synonym(s):Ethynylcyclopropane

CAS NO.：6746-94-7
Empirical Formula: C5H6
Molecular Weight: 66.1
MDL number: MFCD02181090
EINECS: 425-430-1
SAFETY DATA SHEET (SDS)
Update Date: 2025-09-09 10:27:52

What is Cyclopropylacetylene?

Preparation

Cyclopropylacetylene was prepared in a two-step procedure by dichlorination of cyclopropyl methyl ketone with phosphorus pentachloride (PCl5) followed by double dehydrohalogenation with a strong base. This sequence presented significant scale-up problems with low overall yields (20-25%).
Similarly, cyclopropylacetylene has been prepared by base-induced dehydrohalogenation of bromovinylcyclopropane . Cyclopropylacetylene has also been prepared from the 1-trimethylsilyl derivative of cyclopropylacetylene, which was prepared by treatment of 5-chloro-1-trimethylsilyl-1-pentyne with lithium diisopropylamide at ?78°C followed by warming to room temperature.

Chemical properties

clear colorless to light yellow liquid

The Uses of Cyclopropylacetylene

Cyclopropylacetylene is used as an organic chemical synthesis intermediate.

Properties of Cyclopropylacetylene

Melting point:	294 °C (decomp)
Boiling point:	79-80 °C
Density	0.7801
refractive index	n20/D 1.4480
Flash point:	-5 °F
storage temp.	2-8°C
solubility	Chloroform, Ethyl Acetate
form	Liquid
color	Clear colorless to light yellow
Specific Gravity	0.797
Water Solubility	Slightly soluble in water.
InChI	InChI=1S/C5H6/c1-2-5-3-4-5/h1,5H,3-4H2
CAS DataBase Reference	6746-94-7(CAS DataBase Reference)
NIST Chemistry Reference	Cyclopropylacetylene(6746-94-7)

Safety information for Cyclopropylacetylene

Signal word	Danger
Pictogram(s)	Flame Flammables GHS02 Corrosion Corrosives GHS05
GHS Hazard Statements	H225:Flammable liquids H315:Skin corrosion/irritation H318:Serious eye damage/eye irritation H412:Hazardous to the aquatic environment, long-term hazard
Precautionary Statement Codes	P210:Keep away from heat/sparks/open flames/hot surfaces. — No smoking. P233:Keep container tightly closed. P273:Avoid release to the environment. P280:Wear protective gloves/protective clothing/eye protection/face protection. P303+P361+P353:IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.