Author(s): Gopi Iloni , Sreenivas Vasam, Veeranna Guguloth and Ravinder Vadde*
A one-flask strategy for the synthesis of novel 4-((3-(aryl) isoxazol-5-yl) methyl)-2H-benzo[b][1,4] oxazin-3(4H)-one derivatives (4a-j) were synthesized by the Cu(I)-catalyzed reaction of in situ generated nitrile oxides with in situ generated N-propargyl 1,4-benzoxazine in good yields and their antibacterial activity was investigated. Among all the synthesized compound 4j have shown very good inhibition against all the tested Gram-positive and Gram-negative bacterial strains with MIC values ranging from 3.12 to 12.5 µg mL-1 . Compound 4f against B. subtilis and K. pneumoniae with MIC value 6.25 µg mL-1 and Compound 4g have shown potent activity against B. subtilis and E. coli with MIC value 12.5 µg mL-1 . Remaining compounds are shown moderate to poor activity as compared to the standard drug Streptomycin.