A green approach for the synthesis of long chain aliphatic acid esters at room temperature

Fischer esterification of long chain aliphatic acids with methanol and ethanol could be promoted by two novel Brønsted acidic ionic liquids that bear an aromatic sulfonic acid group on the imidazolium or pyridinium cation. The reactions carried out smoothly at room temperature with good to excellent isolated yields (85–99%) under solvent-free conditions in the presence of 10 mol% ionic liquids. These ionic liquids could be recovered easily and recycled three times without any significant loss in catalytic activity.

Graphical abstractTwo novel Brønsted acidic ionic liquids (2a and 2b) served as efficient and reusable catalysts, which could promoted Fischer esterification of long chain aliphatic acids with methanol and ethanol, the reactions carried out smoothly at room temperature with excellent yields.Figure optionsDownload full-size imageDownload as PowerPoint slide