Which of the following is formed when propene is heated with bromine at high temperature?
Which of the following is formed when propene is heated with bromine at high temperature?
1, 2-Dibromopropane
1-Bromopropane
2-Bromopropene
3-Bromopropene
Solution
When alkenes are heated with $\mathrm{Br}_2$ or $\mathrm{Cl}_2$ at high temperature, hydrogen atom of allylic carbon is substituted with halogen atom giving allyl halide.
$\begin{aligned}
& \mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}_3+\mathrm{Br}_2 \longrightarrow \mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}_2 \mathrm{Br}+\mathrm{HBr} \\
& \text { 3-Bromopropene } \\
&
\end{aligned}$