Abstract
Background: The objective of this study was to develop a practical green procedure to synthesize quinoxalines and bis-quinoxalines and evaluate their inhibitory effects on the viability of A431 human epidermoid carcinoma cells. Method: A series of quinoxaline and bis-quinoxaline derivatives have been designed and synthesized following a microwave-assisted and bismuth nitrate-catalyzed eco-friendly route. A detailed comparison has been made between microwave-induced protocol with the reactions occurred at room temperature. The structure of the compounds have been elucidated by various spectroscopic methods and finally confirmed by x-ray crystallographic analyses. Results: Two quinoxaline derivatives, compounds 6 and 12 have demonstrated inhibitory effects on the viability of A431 human epidermoid carcinoma cells when compared with HaCaT nontumorigenic human keratinocyte cells. Conclusion: Notably, compound 6 inhibits Stat3 phosphorylation/activation in A431 skin cancer cells.