Phenol is more important than most people realize. It can be found in many consumer products including aspirin, head lights, gas tanks, billiard balls, nylon, wintergreen gums, Pepto Bismol, deodorant and more. A side product in the manufacture of phenol is acetone which is also used in the private sector in plastics, solvents, and more.

The high-yield manufacture of phenol uses the concepts of peroxidation and cleavage. Cumene (i-propyl benzene) is oxidized by exposure to air to temporarily produce cumene hydroperoxide. The cumene hydroperoxide is simply cleaved at the top of the benzene ring using an acidic catalyst to produce the two usable products of phenol and acetone. The catalyst is extracted and the phenol/acetone mixture is fractionated and purified. Under optimal conditions, 1.31 tons of i-propyl benzene (cumene) will produce 1 ton of phenol and 0.615 tons of acetone. The end-product phenol purity is at 99.99 wt % with total impurities of only 60 ppm. This process is termed the Hock process after being discovered by Hock and Lang in 1944. This process was ideal since both products were useful and relatively pure. Modern demand, however, for phenol is increasing at a higher rate than acetone. This means that the future may classify acetone as a partial waste product. More information on the Hock Process of manufacturing Phenol can be found here which expands on the Benzene-Free Synthesis of Phenol or here which discusses Selective decomposition of cumene hydroperoxide into phenol and acetone by a novel cesium substituted heteropolyacid on clay.

Let’s look at some chemical structures:
One problem occurs with aspirin is that it has a destructive effect on the blood vessel walls and inhibit the synthesis of prostacyclin. To resolve this problem, we can use potential anti-platelet agents including the O-acyl esters which are synthesized from salicylic acid and diflunisal. Those agents work by acylation of cyclooxygenase and have a higher extraction than aspirin. That makes them yield a greater selectivity in their effect on platelet inhibition relative to prostacyclin inhibition on vessel walls.

The actual reaction is shown on the top.