Synthesis, Antioxidant, Antifungal and Antibacterial Activities of New Class of Fused Isoxazole-Pyrimidines and Pyrazole-Pyrimidines as Five and Six Membered Heterocyclic Compounds

One series of total 5 phenylisoxazolo[4,3- d ]pyrimidine and five series of total 22 pyrazolo[4,3- d ]pyrimidine compounds were designed, synthesized and evaluated for anti-oxidant, antibacterial and antifungal activities. Compounds pyrazolo[4,3- d ]pyrimidine derivatives ( VIIIa' – d' ), ( IXa' – d' ) and ( XIa' – d' ) exhibited significant antioxidant activity at 10 µg/mL better than compounds isoxazolo[4,3- d ]pyrimidine derivatives ( IIIa – e ). The maximum anti-oxidant and anti-lipid peroxidation activities were showed for evaluated compound ( IXb' ) 90% and 68% activities comparable to Vitamin-C and with Vitamin-E which showed 92% and 70% of activity respectively. Furthermore, compounds ( VIIIa' – d' ) showed the highest antifungal activity against Botrytis cinerea and Alternaria solani species whereas compounds ( IXa' – d' ) showed the highest antifungal activities against Cercospora arachidicola and Gibberellazeae zeae species. Finally as antibacterial activity the evaluated compounds ( VIIIa' – d' ) showed pronounced antibacterial activities against Escherihia coli strain. All newly synthesized compounds structures were established on the basis of their elemental analysis and spectral IR, 1 H NMR and 13 C NMR.