10 Halogen Derivaties

3. Give reasons

iv. Alkyl halides are generally not prepared by free radical halogenation of alkanes.


  • The free radical halogenation of alkanes indeed results in the formation of a mixture of mono and polyhalogenated compounds.
  • This occurs because the radical halogenation process is highly non-selective and can lead to multiple substitution reactions at various carbon atoms within the alkane molecule.
  • Consequently, obtaining a pure product, such as a specific alkyl halide, can be challenging through free radical halogenation.
  • Therefore, this method is generally not suitable for the precise preparation of individual alkyl halides when high selectivity and purity are required. Alternative methods, such as nucleophilic substitution reactions or the use of specific reagents, are often preferred for the controlled synthesis of alkyl halides.

10 Halogen Derivative Page 232