The yield of material can be somewhat increased by working with small lots
(25 g. of bromostyrene).

The use of steel or copper vessels in place of a glass flask seems
to diminish the yield slightly.


3. Other Methods of Preparation

Phenylacetylene has been prepared by the elimination of carbon
dioxide from phenylpropiolic acid by means of phenol[1] or aniline[2]
or by heating with barium hydroxide;[3] from styrene dibromide,
by heating with potassium hydroxide in alcohol;[4] by heating b-bromo
or chloro styrene with sodium ethylate or potassium hydroxide
in alcohol;[5] by passing the vapors of a-dichloroethylbenzene over
hot soda lime;[6] by the action of alcoholic potassium hydroxide
on dibenzal-acetone tetra-bromide;[1b] by the action of aqueous
potassium hydroxide on phenyl propargylaldehyde;[2b] by the action
of molten potassium hydroxide on b-bromo-styrene.[3b]


[1] Ber. 20, 3081 (1887).

[2] Rec. trav. chim. 16, 157 (1896).

[3] Arm. 221, 70 (1883).

[4] Ann. 154, 155 (1870); 235, 13 (1886); Bull. soc. chim. 35, 55
(1881); (3) 25, 309 (1901).