Posted by: djay
a friend of mine did that experience and the yield was less 15% and if you leave KMnO4 and Ar-CH3 for a long time, the reaction will be close to ozonolysis with some secondary products.
First the toluene oxidize to benzilic alcohol, then to benzaldehyde an finally to benzoic acid, the subproducts are the alcohol and the benzaldehyde.
If you leave the reaction for a long time you should obtain the benzoic acid as the major product