PHENYLACETYLENE

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Phenylacetylene
Systematic name	Ethynylbenzene
Chemical formula	C8H6
Molecular mass	102.133 g/mol
Density	0.93 g/cm³
Melting point	–45 °C
Boiling point	142-144 °C
CAS number	[536-74-3]
SMILES	C#Cc1ccccc1

'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.

Contents

Preparation

Reactions

See also

References

Preparation

In the laboratory, phenylacetylene can be prepared by elimination of hydrogen bromide from styrene dibromide using sodium amide in ammonia.^[1]
It can also be prepared by the elimination of hydrogen bromide from bromostyrene using molten potassium hydroxide.^[2]

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.

See also

★ Alkyne

★ Alkyne trimerisation

References

1. Organic Synthesis, http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0763
2. Organic Synthesis, http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0438