Synthesis, crystal structure and antimicrobial activity of 2-((2-(4-(1H-1,2,4-triazol-1-yl)phenyl)quinazolin-4-yl)oxy)-N-phenylacetamide derivatives against phytopathogens.

A total of eighteen 2-((2-(4-(1H-1,2,4-triazol-1-yl)phenyl)quinazolin-4-yl)oxy)-N-phenylacetamide derivatives were designed and synthesized, via hybrid pharmacophore approach. Among these compounds, chemical structure of compound 4a was unambiguously confirmed by means of single-crystal X-ray diffraction analysis. All the compounds were evaluated in vitro for their inhibition activity against several important phytopathogenic bacteria and fungi in agriculture. The obtained results indicated that several compounds demonstrated potent antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo). For example, compounds 4c, 4g and 4q had EC50 values of 35.0, 36.5 and 32.4 µg/mL toward this bacterium, respectively, around 1.5 times more active than commercial bactericide bismerthiazol (EC50 = 89.8 µg/mL). Additionally, compounds 4j and 4p were found to display comparable antifungal activity against Gloeosporium fructigenum at 50 µg/mL, to commercial fungicide hymexazol. Finally, the relationships between antibacterial activities and molecular structures of this class of compounds were discussed in detail.