Biphenol compound preparation method

The invention provides a biphenol compound preparation method. The biphenol compound preparation method is characterized in that 2, 6-dialkyl phenol is used as a raw material and is subjected to oxygen or air catalytic oxidation so as to prepare a 2, 2', 6, 6'-tetraalkyl-4, 4'- biphenol product. The reaction is carried out in the following two steps under the condition of the inexistence of a solvent: firstly smelting the 2, 6-dialkyl phenol in an inert gas environment, then mixing with hydroxide of alkali metals or alkaline-earth metals or organic salt, heating to 110-190 DEG C, and carrying oxidative coupling reaction under the condition of introducing oxygen or air; and then carrying out reduction reaction at 150-250 DEG C in an inert gas environment so as to obtain 2, 2', 6, 6'-tetraalkyl-4, 4'- biphenol product. The biphenol compound preparation method has the advantages that the yield is high, the conversion rate of the 2, 6-dialkyl phenol can reach 85-90%, and the content of the 2, 2', 6, 6'-tetraalkyl-4, 4'- biphenol product is higher than 98.5%; no solvents are used in the whole preparation process, the continuity of the production process can be realized, and the 2, 6-dialkyl phenol which is unreacted and separated out from a reaction system has good quality and can directly serve as the raw material to be recycled, so that the productivity is further increased.