Sulfanilic Acid Supported on Magnetic Nanoparticles as a Green Catalyst for the Sonosynthesis of 1,4-Diazepines Containing Tetrazole Ring

Magnetic nanoparticle-supported sulfanilic acid (MNPs-PhSO3H) has been used as an efficient catalyst for the preparation of 1,4-diazepines containing tetrazole ring. The catalyst has been characterized by FT-IR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscope), XRD (X-ray diffraction) and VSM (vibrating-sample magnetometer). The present synthetic protocol provides several advantages such as easy work-up, excellent yields, short reaction times, reusability of the catalyst and low catalyst loading. The present catalytic procedure is extensible to a wide diversity of substrates for the synthesis of a variety-oriented library of 1,4-diazepines containing tetrazole ring.