Nano n-propylsulphonated γ-Fe2O3: A novel magnetically recyclable heterogeneous catalyst for the efficient synthesis of bis(pyrazolyl)methanes in water

Nano n-propylsulphonated gamma-Fe2O3 (NPS-gamma-Fe2O3) was applied as a new magnetically recyclable heterogeneous catalyst for the efficient one-pot synthesis of bis(pyrazolyl)methanes in water. The catalyst was easily isolated from the reaction mixture by a magnetic bar and reused at least five times without significant degradation in activity.