Question

a) For the preparation of alkyl chlorides from alcohols, thionyl chloride (SOCl₂) is preferred. Give reason. 

b) Haloalkanes undergo b – elimination reaction in presence of alcoholic potassium hydroxide. 

i) Which is the major product obtained by the b- elimination of 2-Bromo pentane? 

ii) Name the rule, which leads to the product in the above elimination reaction. 

c) Write the chemical equation for the preparation of toluene by Wurtz-Fitting reaction.

Answer 1

a) SO₂ and HCI being escapable gases, the reaction of alcohols with thionyl chloride gives pure alkyl chlorides.

R-OH + SOCI₂ → R-CI + SO₂ + HCI

b) i) pent-2-ene is the major product since it has a greater number of alkyl groups attached to the doubly bonded carbon atoms.