Hi friends,
Carboxylic acids can be straightaway reduced to alkanes using hydrogen iodide in conjunction with red phosphorus. It is a mighty strong reducing agent. So to reduce benzoic acid to toluene, use HI/Red P.
Another method, although not so much well known, is to use the Arndt Eistert synthesis to increase the carbon chain of benzoic acid by a -CH2 group. This would make it benzyl carboxylic acid, Ph-CH2-COOH. Now you can perform a decarboxylation using NaOH/CaO to get toluene.
If you want to find the suppliers of iodine plz click the link below
http://www.chemicalregister.com/find/Find.asp?SearchTy=PName&SearchSu=iodine&SearchKe=AllKey&SearchLo=ALL&x=0&y=0
