Synthesis and Biological Evaluation of Isatin Derivatives as Antibacterial Inhibitors

Abstract

Herein, 2'-amino-6'-(ethylthio)-2-oxo-1'H-spiro[indoline-3,4'-pyridine]-3',5'-dicarbo-nitrile I and 2-(2-oxoindolin-3ylidene)hydrazine-1-carbox-imidamide II were served as prestarting intermediates for the production of polyfunctional substituted heterocycles like; pyrazole, pyridine, imidazole, and pyrimidine. Subsequently, representative chemicals of the manufactured series were verified and assessed as antibacterial inhibitors. Spiro-indoline pyridine I was prepared to be used as a beginning material for manufacturing assorted novel heterocyclic compounds containing an isatin moiety. Derivative I was obtained via the reaction of isatylidene malononitrile with malononitrile and ethyl thiol in the presence of ammonium acetate. The starting compound I was permitted to combine with carbon disulfide in boiling pyridine to afford the carbamodithioic acid derivative III. Also, the reaction of compound I with triethyl orthoformate, maleic anhydride, dimethylformamide, dimethyl acetal, hydrazine hydrate, and diethyl malonate yielded compounds IV, V, VI, VII, and VIII respectively. Moreover, the reaction of the ketonic carbonyl group of isatin with aminoguanidine salt in aqueous alcohol when there was a catalytic amount of sodium bicarbonate yielded compound II. Likewise, carboximidamide derivative II reacted with active methylene compounds such as malononitrile and its derivatives; namely, ethoxy methylene malononitrile and chloroacetonitrile to afford compounds XI, XII, and IX, respectively. On the other hand, compound II interaction with dimethyl acetylenedicarboxylate allowed a heterocyclic imidazole derivative to be obtained.