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

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