Phenylacetylene

Chembox new
Name = Phenylacetylene
ImageFile = Phenylacetylene.svg
ImageName = Phenylacetylene
ImageFile1 = Phenylacetylene-3D-balls.png IUPACName = Ethynylbenzene
Section1 = Chembox Identifiers
CASNo = 536-74-3
SMILES = C#Cc1ccccc1
Section2 = Chembox Properties
Formula = C₈H₆
MolarMass = 102.133 g/mol
Density = 0.93 g/cm³
MeltingPt = –45 °C
BoilingPt = 142-144 °C

Phenylacetylene is an alkyne hydrocarbon containing a phenyl group. It exists as a colorless, viscous liquid. In research, it is sometimes used as an analog for acetylene; being a liquid, it is easier to handle than acetylene gas.

Preparation

In the laboratory, phenylacetylene can be prepared by elimination of hydrogen bromide from styrene dibromide using sodium amide in ammonia. [Organic Synthesis, http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0763] It can also be prepared by the elimination of hydrogen bromide from bromostyrene using molten potassium hydroxide. [Organic Synthesis, http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0438]

Reactions

* Phenylacetylene can be reduced (hydrogenated) by hydrogen over Lindlar catalyst to give styrene.

* It undergoes a metal catalyzed trimerization to give 1,2,4- (97%) and 1,3,5-triphenylbenzene..

* It undergoes gold-catalyzed hydrolysis to give acetophenone.

ee also

* Alkyne
* Alkyne trimerisation

References