Process for producing 3,3,5-trimethylcyclohexylidenebisphenols

摘要

A process for producing a 3,3,5-trimethylcyclohexylidenebisphenol of formula (11): wherein R<1> and R<2> can be the same or different and represent hydrogen or C1-C4 alkyl, each R1 substituent being the same or different and each R2 substituent being the same or different, provided that the R<1> and R<2> substituents on a given phenyl moiety are not simultaneously C4 alkyl, which process comprises: (a) reacting a phenol (A) of formula (I) wherein R<1> and R<2> are as defined above, with 3,3,5-trimethylcyclohexanone (B) at a molar ratio ((A)/(B)) of from 3 to 7 in the presence of an acid catalyst until the 3,3,5-trimethylcyclohexanone (B) exhibits at least 90 mol% conversion; and (b) adding a phenol (A) of formula (I) wherein R<1> and R<2> are as defined above and/or an aromatic hydrocarbon (C) to the thus obtained reaction mixture.