Benzene, CO, PBr5, MOM-Cl they are all dangerous reagents.
Use Toluene + NBS --> Benzyl-Bromide
Then use sodium methoxide as above.
By the way Gatterman Koch reaction and the F-C alkylation posted by Ad Majorem Dei Gloriam require a high pressure reactor, very dangerous.
There are always dozens of ways to obtain a product, but which one is the safest ?