Mechanism of the β-Hydroxyethylation of Hydroquinone Catalyzed by Imidazole

The results showed that the hydroxyethylation reaction occurs first on the imidazole ring to generate 1-(2-hydroxyethyl)imidazole derivative when the nitrogen atom at position 1 of the imidazole ring has a hydrogen atom.

There are no significant differences for the catalytic performance of 1-substituted, 2-substituted, and multi-substituted imidazoles. Imidazole catalysts activate EC through a nucleophilic catalysis mechanism rather than activating HQ via a basic mechanism. The nitrogen atom at position 3 of the imidazole ring is the active site for activating EC ring-opening.