Process for the formation of 2,6-diphenyl-phenol

Claim 1

In a process for the preparation of 2,6-diphenylphenol, the steps comprising: a. passing a reaction mixture consisting of an aqueous alkaline catalyst and a cyclic ketone selected from the group consisting of cyclohexanone and mixtures thereof with bicyclic condensation products of cyclohexanone successively through at least two condensation reactors in a condensation reactor zone wherein the reaction temperature is from 150° to 200° C.; b. removing said condensation product from said reactor zone when it contains a maximum of 70% of tricyclic ketones by weight; c. collecting and condensing the vapors above the condensation reactors in the reactor zone and passing the same to a decantor wherein a water phase and a cyclohexanone phase is formed; d. separating said cyclohexanone phase from the water phase and recycling said cyclohexanone phase to the first condensation reactor in said reaction zone whereby it acts as a source of cyclohexanone and as a solvent for the reaction mixture; e. cooling said condensation product as it leaves said reaction zone; f. passing said condensation product to a neutralizer and neutralizing by adding an acid to form an aqueous phase and an organic phase; g. separating said organic phase from said aqueous phase; h. passing said organic phase through a first distillation column to remove water, a second distillation column to remove bicyclic autocondensation products of cyclohexanone which are recycled to the first condensation reactor, and a third distillation column to separate an isomeric mixture of tricyclic ketones from the remainder of the organic phase; i. passing said isomeric mixture of tricyclic ketones through a dehydrogenation catalyst in a fixed bed dehydrogenation reactor maintained at a temperature from 240° to 360° C. to produce a mixture of 2,6-diphenylphenol and partially dehydrogenated by-products; and j. recovering 2,6-diphenylphenol from said mixture.