Question

tolune to benzaldehyde

Answer 1

30 g of toluene are heated to 60° C with 1500 g of sulphuric acid (d=1.5 g/ml) in a 2-l round-bottomed flask fitted with a reflux condenser and mechanical stirrer. 250 g of cerium dioxide are gradually added, and the temperature allowed to rise to 90° C. When no more cerium dioxide remains, the whole is steam distilled until no more benzaldehyde passes over which is extracted from the distillate with ether. The extract is dried over calcium chloride, the ether removed on a water bath, and the residue distilled in a current of carbon dioxide, the fraction 177-182° C being retained. Yield 70%.