General Methods of Preparation of Haloalkanes
1. From Alcohols
In Groove’ s method, ZnC12 is used to weaken the C-OH bond. In case of 3 ° alcohols, ZnC12 is not required.
The reactivity order of halogen acids is HI > HBr > HCl.
Darzen procedure is the best method for preparing alkyl halides from alcohols since both the by products( SO2 and HCl) are gaseous and escape easily.
2. Free Radical Halogenation of Alkanes
Addition of Hydrogen Halides on Alkenes