Chemoselective synthesis of 5-amino-7-bromoquinolin-8-yl sulfonate derivatives and their antimicrobial evaluation

Abstract

A series of new 5-amino-7-bromoquinolin-8-ol sulfonate derivatives 5(a–j) were synthesized from 8-hydroxyquinoline through multi-step process with high yields using mild, efficient and conventional methods. Chemoselectivity was observed during the transformation of 5-amino-7-bromoquinolin-8-ol to 5-amino-7-bromoquinolin-8-ol sulfonate with various sulfonylchlorides exclusively to afford sulfonate derivatives. Also, the products were investigated for their in vitro antimicrobial activities and compared with the standard drugs. Among all the synthesized compounds 5-amino-7-bromoquinolin-8-yl biphenyl-4-sulfonate (5b) and 5-amino-7-bromoquinolin-8-yl 2-hydroxy-5-nitrobenzenesulfonate (5g) have showed potent antibacterial activity, whereas 5-amino-7-bromoquinolin-8-yl biphenyl-4-sulfonate (5b) and 5-amino-7-bromoquinolin-8-yl 2-hydroxy-5-nitrobenzenesulfonate (5g) possessed potent antifungal activities among all the tested pathogens.

Graphical Abstract

Keywords:

• 8-Hydroxy quinoline
• 5-amino-7-bromoquinolin-8-ol
• chemoselectivity
• sulfonation
• antimicrobial activity

Acknowledgments

The authors are highly thankful to Department of Chemistry and Department of Biochemistry for providing lab and biological activity facilities. Authors are also thankful to B. V. K. Prasad and S. Mallikarjun Reddy for their technical assistance.