Expeditious microwave-assisted synthesis and bio-evaluation of novel bis (trifluoromethyl) phenyl-triazole-pyridine hybrid analogues by the click chemistry approach

• Published in: Research on chemical intermediates 2018, Vol.44 (1), p.585-599
• Main Authors: Jha, Anjali, Atchuta Ramarao, T.
• Format: Article
• Language: English
• Subjects: Alkylation; Bacteria; Catalysis; Chemical synthesis; Chemistry; Chemistry and Materials Science; Cross coupling; E coli; Fungi; Fusarium; Inorganic Chemistry; Palladium; Physical Chemistry; Salmonella
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-017-3121-2

A series of novel 1,2,3-triazole-2,4-bis(trifluoromethyl) phenyl pyridine hybrids 7a – n were efficiently synthesized by the click chemistry approach. The precursor 6-(3,5-bis(trifluoromethyl)phenyl)pyridin-3-ol 3 was obtained by palladium catalyzed cross coupling between 6-bromo-3-pyridinol (2) and (3,5-bis (trifluoromethyl) phenyl) boronic acid (1) in a microwave under nitrogen conditions, which was further alkylated with propargyl bromide 4 in DMF in the presence of K 2 CO 3 and a catalytic amount of TBAI to get 5 . All products obtained in each step were well characterized by various spectral studies and found consistent with expected structure. The triazole derivatives 7a – n were evaluated against human bacterial pathogens, namely, Escherichia coli , Salmonella typhimurium and Staphylococcus aureus and fungal strains Aspergillus niger , Fusarium solani and Penicillium notatum for in vitro activity. Among them, 7e and 7m emerged as potential compounds comparable with the standard drug Ciprofloxacin against tested bacteria, and it is worthwhile to notice that compound 7k emerged more potent than the standard Griseofulvin against fungi.