Improved Synthesis of Para-Aminosalicylic Acid on Organometallic Catalysts

An improved synthesis of p -aminosalicylic acid (PASA) via hydrogenation of p -nitrosalicylic acid in the presence of organometallic palladium and nickel catalysts under mild conditions is proposed. The catalyst properties are compared to those of classical heterogeneous analogs used in modern pharmaceutical production. The organometallic catalysts are found to exceed significantly their heterogeneous analogs in stability, selectivity, and activity. The developed catalytic synthesis of PASA can be considered an alternative to the existing method and an environmentally efficient method for obtaining PASA that meets the main criteria of green chemistry.