Brønsted-acidic ionic liquids as catalysts for synthesizing trioxane

The synthesis of trioxane has been made from a 60 wt% aqueous formaldehyde solution in the presence of 2 wt% pyrrolidinonium-based IL catalysts or sulfuric acid. Both the formation rate of trioxane and the equilibrium yield of trioxane are greatest when sulfuric acid was used. However, the acidity of the reaction solution is also significantly increased as sulfuric acid was used in place of an IL catalyst. A high yield of trioxane and a high selectivity are the main advantages of using the pyrrolidinonium-based ILs in synthesis of trioxane.111