Dehydrogenation of 2-(1-Cyclohexenyl)cyclohexanone with Palladium Catalyst

Abstract The dehydrogenation reaction of 2-(1-cyclohexenyl)cyclohexanone was carried out in the presence of 5% palladium-on-charcoal at temperatures 280, 300, and 320 °C, the reaction time being 1/2—8 hr. o-Cyclohexylphenol and o-phenylphenol were obtained as dehydrogenation products, and dibenzofuran as the cyclization product via o-phenylphenol. In a short reaction time, 2-cyclohexylcyclohexanone was formed together with the dehydrogenation products. The compound disappeared, the amount of two phenols and dibenzofuran increasing with reaction time. The dehydrogenation process is discussed.