Patent ID: 6118029
Filing Date: 2000-09-12
Classification: C07C

Abstract:
A process for producing 3,3',5,5'-tetra-t-butylbiphenol, comprising conducting an oxidative dimerization of purified 2,6-di-t-butylphenol (i) or crude 2,6-di-t-butylphenol (ii), said crude 2,6-di-t-butylphenol being obtained by reacting isobutylene with phenol in the presence of an aluminum catalyst, and removing the aluminum catalyst, wherein the oxidative dimerization of (i) or (ii) is performed in the presence of an alkali metal catalyst mixture to thereby obtain 3,3',5,5'-tetra-t-butylbiphenol,wherein said catalyst mixture comprises:(1) alkali metal catalyst and alkylphenols, or(2) alkali metal catalyst, alkylphenols and phenol.