SYNTHESIS, F-19 NMR SPECTRAL STUDIES AND ANTIBACTERIAL EVALUATION OF SOME NEW FLUORINE CONTAINING INDOLE-DERIVATIVES

The condensation behaviour of various fluorine containing 3-indolylimino derivatives with mercaptoacetic acid and with chloroacetyl chloride has been studied. The cyclocondensation of 3-arylimino-2H-indol-2-ones(III; Ar = 4FC6H4, 3CF3C6H4, 2Cl3CF3C6H3, 2,3,4,5-tetra-FC6H and 2,3,4,6-tetra-FC6H) with mercaptoacetic acid yielded 3′-phenylspiro [3H-indole-3,2′-thiazolidine]-2,4′(1H)-diones (IV) in 75-90% yields. Reaction of anil (III; Ar = 2,3,4,5-tetra-FC6H) with chloroacetyl chloride gave spiro[azetidine-2,3′- 3H indole]-2′, 4(1′H)-dione (VI) in 75% yield. However, similar reactions in the case of 3-(pentafluorophenylimino)-2H-indol-2-one did not give the expected spiro compounds: 3-indolylmercaptoacetic acid (V) was obtained with mercaptoacetic acid, while the product from chloroacetyl chloride could not be characterized. Further, the reactions of various fluorine containing isatin-3-hydrazones (VII; Ar = 4C6H4, C6F5, 1,2,4-triazino [5,6-b] indole, benzimidazole) with mercaptoacetic acid also did not give corresponding spiro compounds and unchanged compounds (VII) were recovered. The compounds synthesized have been characterized by their analytical and spectral (IR, 1H NMR & 19F NMR) data, and were screened for antibacterial activity. © 1990.