Question

How will you convert propan-2-ol to 1-bromopropane?

Answer 1

To convert propan-2-ol to 1-bromopropane, follow this two-step reaction sequence:

1. Dehydration of Propan-2-ol to Propene: Propan-2-ol (CH₃ – CHOH – CH₃) is heated with concentrated H₂SO₄. It undergoes dehydration, giving propene (CH₃ – CH = CH₂).
   \[\ce{\underset{propan-2-ol}{CH3 - CHOH - CH3} + HBr ->[conc. H2SO4][Heat] \underset{propene}{CH3 - CH = CH2}}\]

2. Addition of HBr to Propene (Peroxide Effect): Propene is treated with HBr in the presence of organic peroxide. Due to the peroxide effect (anti-Markovnikov’s rule), Br attaches to the terminal carbon.
   \[\ce{\underset{prop-1-ene}{CH3 - CH = CH2} + HBr ->[peroxide][] \underset{1-bromopropane}{CH3 - CH2 - CH2 - Br}}\]