Synthesis of novel thiazole, pyranothiazole, thiazolo[4,5-b]pyridines and thiazolo[5′,4′:5,6]pyrano[2,3-d]pyrimidine derivatives and incorporating isoindoline-1,3-dione group

Background: Thiazole is a core structural motif presents in a wide range of natural products. Thiazole derivatives also have a wide range of medicinal and biological properties. Results: The reaction of hydrazonoyl halides with 2-(1-(4-(1,3-dioxoisoindolin-2-yl)phenyl)ethylidene)hydrazine-carbothioamidein ethanol and triethylamine yielded 2-(4-(1-(2-(4-(2-Arylhydrazono)-5-s-4,5-dihydrothiazol-2-yl)hydrazono)-ethyl)phenyl)isoindoline-1,3-dione and 2-(4-(1-(2-(5-(2-Arylhydrazono)-4-oxo-4,5-dihydrothiazol-2-yl) hydrazono)ethyl)-phenyl)isoindoline-1,3-dione. The reaction of 2-(4-(1-(2-(4-oxo-4,5-dihydrothiazol-2-yl)hydrazono) ethyl)phenyl)isoindoline-1,3-dione with arylidenemalononitrile also yielded 5-amino-2-(2-(1-(4-(1,3-dioxoisoindolin-2-yl)phenyl)ethylidene)hydrazinyl)-7-substituted-7H-pyrano[2,3-d]thiazole-6-carbonitrile. The structures of the newly synthesized compound were elucidated whenever possible on the basis of elemental analysis, spectral data, and alternative synthetic routes. Three of them were evaluated against a breast cancer cell line for their antitumor activity. Conclusions: Compound (1) has been shown to be useful in the synthesis of a new series of 1,3-thiazole, pyrano[2,3d]thiazole and 4,5-dihydrothiazolo[4,5-b]pyridine derivatives using hydrazonoyl halides as precursors. The anticancer efficacy of compounds (9b), (9e), and (9f) against MCF-7, a breast cancer cell line, was also compared to the standard anticancer drug doxorubicin.