In wourtz reaction a solution of alkyl halide in ether on heating with sodium gives alkane.

| An alkyl halide on Wurtz reaction leads to the formation of symmetrical alkane having an even number of carbon atoms. Two different alkyl halides, on Wurtz reaction give all possible alkanes. |
CH3X + Na + C2H5X → CH3CH2CH3 + CH3CH3 + CH3CH2CH2CH3
The different involved are steps are:
CH3X + 2Na + C2H5X → CH3CH2CH3 + 2NaX
CH3X + 2Na + C2H5X →CH3CH3 + 2NaX
C2H5X + 2Na + C2H5X → C2H5C2H5 + 2NaX
The separation of mixture into individual members is not easy because their boiling points are near to each other and thus Wurtz reaction is not suitable for the synthesis of alkanes containing odd number of carbon atoms.
| When Zn is used in Wurtz reaction in place of Na, the reaction is named as Frankland method. |
Limitations of Wurtz reaction :
a.Methane can not be obtained by this method
b.The reaction fails in case of tertiary halides
Mechanism of Wurtz reaction :
The mechanism of Wurtz reaction is although not clear however two mechanisms are proposed for this reaction.
The first proposed mechanism of Wurtz reaction involved formation of an Intermediate organometallic compound:
RX + 2Na → [RNa] + NaX
Intermediate
RX + [RNa] → R-R + NaX
Another proposed mechanizm of Wurtz reaction involved formation of Intermediate free radicals:
RX + Na → R. + Nax
Free radicals
R. + R. → R-R