Nano CuO–Ag‐catalyzed synthesis of some novel pyrano[2,3‐d] pyrimidine derivatives and evaluation of their bioactivity

Abstract A simple, highly efficient, and green method is developed for the synthesis of pyrano[2,3‐d] pyrimidine derivatives via Knoevenagel and Michael addition in the presence of nano CuO–Ag as a catalyst. The structures of synthesized target compounds 5a–l were confirmed by spectral and elemental analysis and were screened for their antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), H 2 O 2 , and NO methods. Their antibacterial activity against Gram‐negative bacteria Pseudomonas aeruginosa and Escherichia coli , against Gram‐positive bacteria such as Bacillus subtilis and Staphylococcus aureus , and antifungal activity against Candida albicans and Candida glabrata was also evaluated. The compounds showed higher bacterial activity than the standard used. Compounds 5b , 5d , 5g , 5h , and 5i exhibited higher free radical scavenging activity than the standard butylated hydroxy toluene (BHT). Compounds 5b , 5d , and 5h showed higher activity on Gram‐positive bacteria, and compounds 5b , 5d , 5h , and 5i showed higher activity on Gram‐negative bacteria than that of standard tetracycline. Compounds 5b , 5j , and 5l showed much higher antifungal activity against Candida globrata and C. albicans than that of standard Griseofulvin.