Study On The Synthesisand Biological Activity Of Heterocyclicamides

For a long time, the heterocyclic compounds play an important role in thedevelopment of the new pesticides. The thiadiazole compound is one of the veryexcellent structural unit and has a very wide range of biological activity. Taking2-methyl-4-(trifluoromethyl)-thiazole-5-carboxylic acid as the starting material, wefirstly synthesize the intermediate5-(2-methyl-4-(trifluoromethyl)-thiazol-5-yl)-[1,3,4]thiadiazol-2-amino group, and then subject it to amidation reaction with different acidchloride, finally obtain seven novel thiadiazole amides. By bioassay shows that thisseries of compounds with fungicidal activity, the compound E in the100μg/mL highconcentration of Physalosporapiricola and Cercosporaarachidicola having bettercontrol effect, its mortality rate of over80%, and the compound G in the100μg/mLhigh concentration of Cercosporaarachidicola having better control effect, its mortalityrate of over80%.The thiazole compounds have been utilized widely as a fungicide, especially thethiazolyl group to attach to a variety of structures through the structural modification,in order to bring in a compound, which would have a wide range of the biologicalactivity. Such as the thifluzamide, which was developed by Monsanto, and itsstructure is shown in Figure I. Taking2-methyl-4-(trifluoromethyl)-thiazole-5-carboxylic acid as the starting material, we react it with thionyl chloride to produce2-methyl-4-(trifluoromethyl)-thiazole-5-chloride, then react it with amidation reactionof an aromatic amine, finally obtain eight novel2-methyl-4-trifluoromethyl-5-thiazolecarboxamides, and measure its bactericidal activity. Particularly the compound8g ofBotrytis cinerea inhibition rate reaches81%, far higher than the control drugthifluzamide. The nicotinamide pesticide compounds in medicine and other fields have a widerange of applications, such as the boscalid, which was developed by Basf, and itsstructure is shown in FigureⅡ. Taking2-chloro-nicotinic acid as the starting materialto yield reaction with thionyl chloride to obtain the2-chloro acid chloride, then react itwith an aromatic amine amidation reaction, finally get six novel2-chloro-nicotinamidecompounds. By bioassay shows that the bactericidal activity of this series ofcompounds ranging, while at higher concentrations, all compounds on Wheat powderymildew and Botrytis cinerea have shown a good antibacterial activity, especially atlower concentrations, compound12f on Wheat powdery mildew and Botrytis cinereabiological activity is better than boscalid. As can be seen from the data of biologicalactivity can be used to control the target compound harmful bacteria.This paper describes the development of the world through agriculture, clearlypointing out the important role of pesticides, especially fungicides in agriculturepossession. Created on the basis of new principles of green pesticides, designe andsynthesize a series of three unreported thiadiazole and thiazole amide and picolinamidederivatives. The structures of compounds were identified by NMR, IR and elementalanalysis. By testing the biological activity of some of the compounds, screen the oneswhich have excellent fungicidal activity.