Synthesis, Antioxidant, and Antibacterial Activities of Two Novel Series of 3,5-Disubstituted Isoxazole Ether-Linked Isoxazolines and 3,5-Disubstituted Pyrazole Ether-Linked Isoxazolines Mediated by Chloramine-T

Abstract: Two short novel series of five membered heterocyclic 3,5-disubstituted–Isoxazole ether-linked Isoxazoline derivatives (Xa–f) and 3,5-disubstituted-Pyrazole ether-linked Isoxazoline derivatives (XIa–f) were synthesized via 1,3-dipolar cycloaddition reaction of Isoxazole ether-linked allyloxymethyl (VI) and pyrazole ether-linked allyloxymethyl (VII) with aromatic aldoximes (VIIIa–f) which undergo oxidative dehydrogenation with chloramine-T (IX) to give 3,5-disubstituted isoxazole ether-linked isoxazoline derivatives (Xa–f) and 3,5-disubstituted pyrazole ether-linked Isoxazoline derivatives (XIa–f) in good yield. The newly synthesized compounds were screened for anti-oxidant and anti-microbial activities. 3,5‑Disubstituted isoxazole ether-linked isoxazoline derivatives (Xc–d) and 3,5-disubstituted Pyrazole ether-linked isoxazoline derivatives (XIc–d) exhibited antioxidant activity at 10 µg/mL, as well as anti-microbial activity at 100 µg/mL compared with standard vitamin C and ciprofloxacin, respectively. Structures of newly synthesized compounds were established on the basis of their elemental analysis and spectral IR, ¹H NMR, and ¹³C NMR.