Prepare Methyl Iodide Using SN2 Mechanism

[Mind_It]

Homework Statement

Hi folks! :)
I have a problem with the following problem.
Take any methyl halide and prepare methyl iodide.Choose the appropriate solvent.

Now what i know is here we are going by SN2 mech and replacing a halide by iodide ion.But the problem i am facing is how can i replace a other halide by a iodide ion because my book says iodide is the best leaving group among all halides.So i am confused how will this happen. ?

 

[siddharth23]

Yes, iodide is the best leaving group. But the solvent can make the difference. For example, the Kharasch addition in the presence of H2O2 breaks the Markonikov's rule. I'm sorry I don't have the details of this reaction, but will check into it.

 

[brake4country]

You can do a displacement reaction with methylbromide:

CH₃Br + KI ----> CH₃I + KBr

You might want to use an aprotic solvent such as DMSO, DMF or acetone.