p-Toluenesulfonic acid → 1-Bromo-2-(1-propen-1-yl)benzene

With the exception of three compounds, the styrene compounds disclosed herein to be utilized for preparing the α-chloro oximes ae known and their preparations are published in the prior art. The compounds not previously prepared are synthesized following well-known published procedures. Thus, 2-bromobenzaldehyde is allowed to react with a Grignard reagent, ethyl magnesium bromide in anhydrous ether, to yield 1(2-bromophenyl)propanol. This propanol derivative is then dehydrated by refluxing it in toluene in the presence of a catalytic quantity of p-toluenesulfonic acid to yield the desired 1-bromo-2-(1-propenyl)benzene. Another previously unknown substituted styrene, namely, 1,2-dichloro-4-(1-propenyl) benzene is prepared by the same general procedure from 3,4-dichlorobenzaldehyde and ethyl magnesium bromide, followed by dehydration of the intermediate substituted propanol.