SYNTHESIS AND BIOLOGICAL-ACTIVITY OF SOME 3-HETEROCYCLYL-4-HYDROXY-6-METHYL-2(1H)-QUINOLONES

The Schiff bases 2a,b, derived from 4-hydroxy-6-methyl-2(1H)-quinolone (1), have been synthesized and allowed to undergo addition of HCN, th iosalicylic acid, thioglycolic acid and HBr. The bromo function of the HBr adduct is susceptible to substitution by different reagents conta ining nitrogen and/or sulphur, the products of which are cyclized to d ifferent heterocyclic systems, viz. 1,3-benzothiazinone, 1,3-thiazolid inone, perhydro-1,2,4-triazine, 5-triazolidine, imidazoline and triazo lidinotriazolidine, as substituents at position-3 of 4-hydroxy-6-methy l-2(1H)-quinolone (1). Some of the newly synthesized compounds are fou nd to be biologically active towards some gram negative and gram posit ive bacteria as well as against yeast. The structure of the new compou nds have been established by chemical reactions and spectral data.