Solid-Phase ortho-Hydroxylation of 2,4-Di-tert-butylphenol and Its Derivatives

Direct phenol–catechol conversion has been realized as a result of the solid-phase reaction of 2,4-di-tert-butylphenol with cuprous oxide under high pressure and shear deformation on the Bridgman anvils. The yield of 3,5-di-tert-butylcatechol in this reaction was about 85%. When cupric oxide was used in the solid-phase process, oxidative coupling of the starting phenol took place, resulting in quantitative formation of tetra-tert-butyl-ortho-bisphenol. The reaction of 6-substituted derivatives of 2,4-di-tert-butylphenol with cuprous oxide was used as an example to demonstrate the possibility of substitutive ortho-hydroxylation yielding 7–20% of pyrocatechols.