Toluene → 2-Methylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

To a stirring mixture of K2S2O8 (1.40 g) and trifluoroacetic acid (5 mL) was added golden-yellow [Rh(CO)2(trifluoroacetate)]x (17 mg). The reaction mixture turned deep purple immediately. Toluene (5 mL) was added, and the dark mixture was stirred under CO (1 atm) at 65° C. (oil bath). The color changed first to dark-red and then tan-brown in 0.5 and 2 hours, respectively. After 54 hours water was added to the mixture. The solution was evaporated, and the resulting mixture was extracted with ether (3×20 mL). The combined ether extracts were dried with MgSO4 and taken to dryness, leaving 470 mg of toluic acid (TON=55). The product was determined by proton NMR spectroscopy to be a mixture of p-toluic acid (90-95%) and m-toluic acid (5-10%).

Provenance & Evidence