Synthesis, Characterization and Biological Activities of New (5′ Phenyl isoxazolinyl thio) 8-substituted (1, 2, 4) triazino (5, 6 b) indole Derivatives

A new series of (5′ Phenyl isoxazolinyl thio) 8-substituted (1, 2, 4) triazino (5, 6 b) indole derivatives were synthesized and evaluated for their antimicrobial and analgesic activities. Different 5-substituted isatins was treated with thiosemicarbazide to form 5-substituted derivatives of isatin 3-thiosemicarbazone (Comp1a-e) which when refluxed with 4% KOH for 4 hrs gave the 8-substituted 5H -2,3 dihydro (1,2,4) triazino (5,6 b) indole 3-thione (Comp 2a-e) which on treatment with cinnamoyl chloride resulted in the formation of 5H-3-(cinnamoyl thio)-8-substituted (1,2,4) triazino (5,6-b) indole (Comp3a-e) which on further refluxing with hydroxylamine hydrochloride, sodium acetate and ethanol for 6 hrs resulted in the formation of 5H-3-(5′ phenyl isoxazolinyl thio) 8-substituted (1,2,4) triazino (5,6 b) indole(Comp 4 a-e). The purity of the compounds monitored by TLC. The structures were confirmed on the basis of IR,¹H NMR spectra. Among the synthesized compounds few compounds have shown promising antibacterial, antifungal, and analgesic activity.