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.