Phenylacetylene

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.

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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