A novel task-specific ionic liquid for Beckmann rearrangement: a simple and effective way for product separation

Under mild conditions and without any additional organic solvents, Beckmann rearrangement of ketoximes was performed in a novel task-specific ionic liquid consisting sulfonyl chloride. Especially for the conversion of cyclohexanone oxime to ε-caprolactam, ε-caprolactam has good solubility in water while the task-specific ionic liquid is immiscible with water, therefore, ε-caprolactam could be easily separated from the reaction system by water extraction.