In the present paper, the super-magnetic iron oxide nanoparticles (Fe₃O₄), functionalized with amine (–NH₂) and carboxyl (–COOH) groups were developed as efficient heterogeneous catalysts for synthesizing the fentanyl citrate compound. The structural analyses (FT-IR, SEM, TEM) have confirmed the successful surface modification while preserving particle morphology and magnetic behavior. The catalysts have exhibited excellent performance across key synthetic steps, enabling high yields under mild conditions and maintaining substantial activity after three consecutive cycles.

The total synthesis of mycophenolic acid (MPA), a potent immunosuppressant, was modified. The obtained mycophenolic acid was suitable for further preparation of new prospective immunosuppressants with improved therapeutic properties.