Synthesis And Herbicidal Activity Of Aryl Thiazole Compounds

In recent years,the development of heterocyclic agrochemicals has become one of a main trend in research on pesticides because of their flexible structure,low mammalian toxicity,high efficiency,and environmental friendliness,which has become the mainstream of new pesticide development today.Especially the thiazole pesticides are one of the hotspots of current research.Fifty eight compounds of aryl thiazole were obtained by 2-chloro-5-nitrobenzoic acid as the starting material via esterification,reduction,diazotization,Hantzsch reaction and acylation reaction.The structures of title products were confirmed by ¹H NMR and MS spectra and part of compounds were confirmed by ¹³C NMR、HRMS spectra precisely.All compounds were evaluated for their herbicidal activity.The biological activity of target compounds had been tested in Zhejiang Chemical Research Institute Co.,Ltd.The results indicated that almost all amide compounds had 80%inhibition of root and stalk of wheat,barnyardgrass,cucumber,rape,radish at 200 mg/L using culture dish.The post-emergence results indicated that at 150g.a.i/ha on weed stem leaf spray treatment,almost all target compounds had no obvious herbicidal activity on monocotyledon weeds,which exhibited high herbicidal activity against dicotyledon weeds,especially it had a significant inhibitory effect on the Amaranthus retroflexus and Eclipta prostrata.Compounds K1,K18,K19,K20,K24,K25,and K31 exhibited 80%inhibition rates against Amaranthus retroflexus;The herbicidal activities of K3,K22,K28,K32,and K37 are slightly weakened,which also achieved 70%inhibition rates.Compounds K1,K14,K19,K24,and K31exhibited 80%inhibition rates against Eclipta prostrate.The herbicidal activities of K18,K20,K30,K32,and K37 slightly decreased,which also reached 70%.