Sustainable Synthesis of Phenazines: A Review of Green Approaches

Abstract: Owing to its momentous significance in the development of new medications, phenazine, and its analogues are successful heterocyclic scaffolds as well as essential building blocks for developing physiologically active chemicals. Traditionally, phenazine and its derivatives have been synthesized using chemical methods that involve toxic organic solvents, dangerous reagents, and the risk of hazardous metal contamination in the final products. These drawbacks have significantly limited the widespread application of phenazine derivatives in therapeutic treatments and the pharmaceutical industry. Consequently, there is a growing demand for environmentally friendly methods that can address these challenges with less environmental damage. As a result, it is now possible to employ green and highly efficient methods for the synthesis of phenazine and its derivatives. These methods include mechanosynthesis, solvent-free and catalyst-free synthesis, green solventbased synthesis, ultrasound-assisted synthesis, microwave-assisted synthesis, and other similar approaches. In light of the fact that the phenazine backbone is a widely present biologically active component and the growing need to decrease the use of hazardous solvents, catalysts, and energy, this review has provided a summary of various sustainable and facile synthetic strategies of phenazine derivatives.