Green Method Synthesis of Pyrano[2,3-d]Pyrimidine Derivatives: Antimicrobial and Electrochemical Behavior Studies

The present work describes one-pot synthesis of pyrano[2,3-d] pyrimidine derivatives using aromatic aldehyde, ethyl cyanoacetate and barbituric or thiobarbituric acid accelerated by microwave irradiation in the presence of agro-waste extract solvent medium with few drops of ethanol as a co-solvent presented. The reaction is optimized by various methods such as magnetic stirring, ultrasound, mechanochemical and microwave irradiation, but the microwave irradiation method excelled product formation faster rate with high yield and purity. The advantages of the present approach are the metal-free, chemical-less, and hazardous solvent-less employed and considered as an eco-friendly protocol for the synthesis of pyrano[2,3-d] pyrimidine derivatives developed. The final product isolated was recrystallized in ethanol and characterized by FT-IR, 1H-, 13C-NMR and LC-MS spectrometry. Further, some of the selected pyrano[2,3-d]pyrimidine derivatives (4a, 4b, 4d, 4f, 4m and 4o) are subjected to electrochemical behavior and anti-microbial activity studies. The anti-microbial activity tested derivatives showed comparable activities, and also electrochemical behavior of oxidation and reduction potentials observed by these compounds.