Synthesis of Novel 2,3-Disubstituted 1,4-Naphthoquinone Derivatives Containing Indole, Quinoline, Thiazole and Imidazole Moieties

The present work describes one-pot multicomponent synthesis in which Michael addition-elimination reactions of the precursors 2-chloro-3-(2-arylhydrazinyl)naphthalene-1,4-dione, 2-amino-4,9-dioxo-4,9-dihydro-1H-benzo[f]indole-3-carbonitrile and 2-amino-4-aryl-5,10-dioxo-5,10-dihydrobenzo[g]quinoline-3-carbonitrile with carbon disulphide, followed by intramolecular cyclization in the presence of pyridine or sulphuric acid or hydrazine have led to formation of the corresponding 3-arylamino-2-thioxo-2,3-dihydronaphtho[2,3-d]thiazole-4,9-dione, 2-thioxo-2H-benzo[f]thiazolo[4,5-b]indole-5-10(3H,4H)-dione, 2-mercaptobenzo[f]thiazolo[4,5-b]indole-5-10(1H,4H)-dione, 11-aryl-2-thioxo-2,3-dihydrotobenzo[g]thiazolo[4,5-b]quinoline-5,10-dione and 1-amino-11-aryl-2-mercapto-1H-benzo[g]imidazo[4,5-b]quinoline-5,10-dione. The synthesized compounds have been identified and their structures are in confirmation with various spectroscopic techniques including IR, H-1 NMR, C-13 NMR and mass spectra.