Synthesis of Phenazin-1-one from 3,4-Dihydroxysalicylaldehyde-Derived Schiff Base via Oxidative Condensation and Diversification

Phenazines are valuable frameworks in medicinal chemistry due to their significant therapeutic potential and tunable optical properties. We present a one-pot sequential addition strategy for synthesizing structurally distinct phenazin-1-ones via PIDA-mediated oxidative condensation. This method operates smoothly under aerobic conditions at ambient temperature, without the use of additives or metal catalysts, yielding a diverse library of compounds. We obtained a bifunctional intermediate through acid-mediated hydrolysis of a phenazin-1-one enamine, which was diversified via glycosylation, N-alkylation, and CuAAC-mediated triazole linkage to demonstrate the utility of this methodology.