β-Hydroxyalkylation of Sterically Hindered Phenols with Epoxides in Acid Medium

摘要

Reactions of 2,6-dialkylphenols with ethylene oxide, propylene oxide and epichlorohydrin in the presence of SnCl4 at the temperature from -5 to +5°C leads to the formation of respective phenols containing a hydroxy group in the β-position of the aliphatic chain of the para-substituent. The conditions for maximum selectivity of the reaction of 2,6-di-tert-butylphenol with ethylene oxide were determined. By HPLC-MS method the directions of the side reactions were explored. The method has been successfully tested in a pilot installation. With 2,6-dimethylphenol instead of 2,6-di-tert-butylphenol a sharp increase occurs in the content of ethers in the reaction product. With epichlorohydrin, 2,6-di-tert-butylphenol affords a product, which is easily converted into an epoxide containing a sterically hindered phenol in its structure.