Heterogeneous Beckmann rearrangements catalyzed by a sulfonated imidazolium salt of phosphotungstate

The heteropolyanion-based ionic liquid (IL) material [MIMPS] ₃PW₁₂O₄₀, propane sulfoacid-functionalized imidazolium salt of phosphotungstate, was used as a solid catalyst for liquid-phase Beckmann rearrangements of ketoximes in the presence of zinc chloride. The resultant liquid-solid biphasic rearrangement reaction of cyclohexanone oxime shows a high yield 83 % with good recyclability. The testing of control catalysts, reaction conditions, oxime substrates, and recycling property were carried out and the results are discussed. Graphical Abstract: The heteropolyanion-based ionic liquid (IL) material [MIMPS]₃PW ₁₂O₄₀, propane sulfoacid-functionalized imidazolium salt of phosphotungstate, was used as a solid catalyst for liquid-phase Beckmann rearrangements of ketoximes in the presence of zinc chloride. The resultant liquid-solid biphasic rearrangement reaction of cyclohexanone oxime shows a high yield 83% with good recyclability. The testing of control catalysts, reaction conditions, oxime substrates, and recycling property were carried out, and the results are discussed.[Figure not available: see fulltext.]