Water → I2-Ionone

A solution of 600 g of a 96% pure pseudoionone in 1,200 ml of methylene chloride was introduced continuously in the course of 10 minutes, while stirring vigorously (800 rpm), through one of the two connections of the reactor, and 1,000 ml of a 96% strength sulfuric acid were fed in simultaneously through the other connection. The product, which was discharged at 42° C., was hydrolyzed in a downstream thin film reactor with 2,000 ml of water, the organic phase was separated off, washed neutral with 2% strength sodium carbonate solution and then with water and freed from solvent under reduced pressure, and the residue was then distilled under 0.2 mbar. 495 g of 97.0% pure β-ionone were obtained, corresponding to a yield of β-ionone of 83.3% of theory. In this case too, the residue produced was a resin which exhibited good flow.