Preparation of uniformly 14C‐labeled and 13C‐enriched catechol and hydroquinone via phenol

Abstract Catechol‐U‐14C and hydroquinone‐U‐14C were prepared from phenol‐U‐14C by mononitration followed by chromatographic separation of o‐ and p‐nitrophenol‐U‐14C. The nitrophenols were separately hydrogenated, and the resulting aminophenols were converted by diazotization followed by hydrolysis to the title diols. Phenol‐U‐14C was synthesized efficiently from benzene by nitration, reduction, diazotization and hydrolysis. A similar series of reactions beginning with benzene‐U‐13C gave phenol, catechol and hydroquinone containing more than 88% total carbon‐13.