Patent ID: 8212084

Claim:
A process for preparing 4,4′-[1-(trifluoromethyl)alkylidene]bis(2,6-diphenylphenols) of the formula (I) where the radical R is unbranched or branched C 1 -C 6 -alkyl or C 1 -C 6 -perfluoroalkyl, which comprises the process steps a) reaction of cyclohexanone in the presence of a basic catalyst to form a reaction mixture comprising the tricyclic condensation products of the formula (IIa), (IIb) and/or (IIc) and water, b) separation of a mixture of the tricyclic condensation products comprising the compounds of the formulae (IIa), (IIb) and/or (IIc) from the reaction mixture formed in step a), c) dehydrogenation of the tricyclic condensation products comprising the compounds of the formulae (IIa), (IIb) and/or (IIc) obtained in step b) in the presence of a supported transition metal catalyst in the condensed phase to form a reaction mixture comprising 2,6-diphenylphenol of the formula (III), d) separation of 2,6-diphenylphenol of the formula (III) from the reaction mixture formed in step c) and e) reaction of the 2,6-diphenylphenol of the formula (III) obtained in step d) with a trifluoromethyl ketone of the formula (IV) where the radical R is as defined for formula (I), in the presence of a strong organic acid to form the 4,4′-[1-(trifluoromethyl)alkylidene]bis(2,6-diphenylphenol) of the formula (I).