Production of 1,2-Cyclohexanedicarboxylates from Diacetone Alcohol and Fumarates

1,2-Cyclohexanedicarboxylates, which are one of the most commonly used plasticizers in the poly(vinyl chloride) (PVC) industry, are generally prepared via the oxidation/esterification/hydrogenation of o-xylene (or naphthalene). Herein, we develop an alternative route toward cyclohexane-based plasticizers using diacetone alcohol and fumarates as the starting materials. The process includes a mild Raney Ni-catalyzed hydrogenation of diacetone alcohol, an one-step dehydration/Diels-Alder reaction of resulting 2-methyl-2,4-pentandiol and fumarates in a choline chloride (ChCl) based deep eutectic solvent (DES), and a further Pd/C-catalyzed hydrogenation. The toxicological tests indicate that the as-synthesized di(2-ethylhexyl) 3,5-dimethylcyclohexane-1,2-dicarboxylate can serve as a safe plasticizer for PVC materials.