ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and biological activities of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety

Bo-Ren Yan, Xin-Yang Lv, Huan Du, Man-Ni Gao, Jian Huang, and Xiao-Ping Bao

State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Centre for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025, China

E-mail: baoxp_1980@aliyun.com

Abstract: A series of novel quinazolinone derivatives containing a 1,2,4-triazolylthioether moiety were synthesised and their antimicrobial activities were evaluated. All the target compounds were characterised by ¹H NMR, ¹³C NMR, ESI-MS, IR and elemental analyses. The single crystal structure of 3-((5-((2-fluorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIi) was also determined. The preliminary bioassays indicated that some of the target compounds possessed good antimicrobial activities. For example, 3-((4-phenyl-5-((4-(trifluoromethyl)benzyl)thio)-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIs) exhibited the best inhibitory effect against Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri with the half-effective concentration (EC₅₀) values of 47.6 μg mL⁻¹ and 22.1 μg mL⁻¹, respectively, which were superior to the commercial bactericide, bismerthiazol. Meanwhile, 3-((5-((4-chlorobenzyl)thio)-4-phenyl-4H-1,2,4-triazol-3-yl)methyl)quinazolin-4(3H)-one (VIIh) exhibited better fungicidal activities against Pellicularia sasakii and Colletotrichum capsici at the concentration of 50 μg mL⁻¹, in comparison with the commercial fungicide, hymexazol.

Keywords: quinazolinone – 1,2,4-triazolylthioether – antimicrobial activity – synthesis

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0034

Chemical Papers 70 (7) 983–993 (2016)