Greener Approach for Synthesis of δ-MnO₂ Nanoparticles: Access to Pharmaceutically Important Pyrimidines and their...

A sustainable approach for pharmaceutically important pyrimidine derivatives is achieved by using biogenically produced single-phase δ-MnO₂ NPs under external ligand-free conditions. The phytochemicals that comprise the extract of Areca Nut Husk (ANH) have been discovered to serve as reducing agents. The role of phytochemicals is not only to aid in the reduction of Mn(VII) into Mn(IV), but they also have an important role in stabilizing the catalyst. The establishment of δ-MnO₂ NPs was confirmed inveterate by FE-SEM, p-XRD, ICP-OES (Mn content = 43.17% w/w), EDX, and with an active Mn content of 43.17% w/w. A series of pyrimidine derivatives were prepared in good yields using a one-pot multicomponent synthesis approach under atmospheric conditions. In addition, hot filtration tests, control experiments, gram-scale synthesis, and mechanistic investigations were demonstrated. Additionally, antimicrobial activity studies of δ-MnO₂ NPs and pyrimidine derivatives against the Gram-negative bacteria E. coli, growth curve and minimum inhibitory concentration were studied.