Process for the preparation of 4,4'-dihydroxydiphenyl ether

Herstellung von 4,4'-Dihydroxidiphenylether aus Diphenylether durch oxidative Jodierung von Diphenylether zu 4,4'-Dijoddiphenylether und/oder 4-Hydroxi-4'-Joddiphenylether und deren basischer Hydrolyse mit Rückgewinnung des Jods und dessen Rückführung in die Diphenyletherjodierung. A method for making 4,4'-dihydroxydiphenyl ether from diphenyl ether by oxidatively iodinating diphenyl ether to 4,4'-diiododiphenyl ether and/or 4-hydroxy-4'-iododiphenyl ether, hydrolyzing this product with a base, recovering iodine from the solution containing iodide, and recycling the iodine to the iodination step.