Combined process of cyclohexyl cyclohexanecarboxylate synthesis from cyclohexanol and CO catalyzed by the Pd(OAc)2–PPh3–p-toluenesulfonic acid system

Objectives . To study the possibility of combining acid-catalytic cyclohexanol dehydration and alkoxycarbonylation formed cyclohexene with carbon(II) oxide in a single reactor order to achieve high yields target cyclohexyl cyclohexanecarboxylate product under mild conditions using Pd(OAc) 2 –PPh 3 – p -toluenesulfonic acid catalytic system. Methods The combined process took place toluene medium periodic steel designed operate at elevated pressure, equipped glass insert, magnetic stirrer, sampler, as well gas input discharge devices. reaction mass components system was placed inside autoclave. samples obtained during were analyzed by gas–liquid chromatography flame ionization detector. Results catalyzed p-toluenesulfonic monohydrate CO catalysis demonstrated. Under (temperature 110°C; pressure 2.1 MPa), yield reached 64.8% 5 h. However, is complicated formation cyclohexanecarboxylic by-product result hydrolysis hydroxycarbonylation. Conclusions reactions intramolecular can be reactor. p-Toluenesulfonic simultaneously act catalyst for co-catalyst palladium–phosphine alkoxycarbonylation. involvement cyclohexene, representing reversible dehydration, factor shifting equilibrium towards cyclohexene. Cyclohexanecarboxylic proposed process. A reduction water due latter course