The Iodination of Aromatic Compounds. III. Halogenation of Aromatic Ethers in the Presence of Hydrogen Peroxide

Abstract

Aromatic ethers are rapidly iodinated when treated in alcoholic solution with iodine and hydrogen peroxide in the presence of a strong mineral acid. High yields of the mono-iodo-derivatives are obtained with anisole and the 2-naphthyl ethers whilst both mono- and diiodination occur readily with the dimethoxybenzenes. In the absence of a mineral acid the reaction is very slow and only poor yield of the iodo-ethers result. A convenient process is described for the preparation of p-chloro- and p-bromo- anisole, and other chloro- and bromo-ethers, the ether being treated with hydrochloric acid and with potassium bromide and sulphuric acid respectively in the presence of hydrogen peroxide.