Brønsted Acidic Deep Eutectic Solvent Based on Imidazole and p-Toluenesulfonic Acid Intensified Prins Condensation of Styrene with Formaldehyde

Brønsted acidic deep eutectic solvent (DES) formed from 1:2 mole ratio of imidazole (Im) and p-toluenesulfonic acid (PTSA) [Im:2PTSA] was applied for the first time to synthesize 4-phenyl-1,3-dioxane (PDO) through Prins condensation of styrene with formaldehyde. The DES [Im:2PTSA] intensified the Prins condensation by breaking up the balance limitation of phase interface between organic styrene and aqueous formaldehyde, increasing the compatibility of both phases, and promoting PDO formation. Brønsted acidic deep eutectic solvent formed from 1:2 mole ratio of imidazole (Im) and p-toluenesulfonic acid (PTSA) [Im:2PTSA] was applied to intensified Prins condensation of styrene with formaldehyde to synthesize 4-phenyl-1,3-dioxane (PDO) by breaking up the balance limitation of organic and aqueous phases, increasing the compatibility of both phases, and promoting the formation of PDO.