Study On The Synthesis And Process Of Fungicide Boscalid And Penthiopyrad

Boscalid is a novel pyridine-carboxamides fungicide. In this paper, boscalid was synthesized using1-chloro-2-nitrobenzene and (4-chlorophenyl)boronic acid as main starting materials, including four steps:First of all,1-chloro-2-nitrobenzene and (4-chlorophenyl)boronic acid were catalyzed with palladium acetate by using Suzuki cross-coupling reaction. And then through the process of reduction, the key intermediate4’-chloro-[1,1’-biphenyl]-2-amine was obtained. And another important intermediate2-chloronicotinoyl chloride was synthesized by chloridizing2-chloronicotinic acid with thionyl chloride. Finally, boscalid was synthesized via the reaction of4’-chloro-[1,1’-biphenyl]-2-amine and2-chloronicotinoyl chloride.The total yield was57%. The chemical structures of the key intermediates and boscalid were characterized by1H NMR.Penthiopyrad is a novel pyrazole-carboxamides fungicide. In this paper,1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carbonyl chloride was synthesized from ethyl4,4,4-trifluoro-3-oxobutanoate reacted with triethoxymethane, and then through the process of cyclization, hydrolysis and chlorination. Then, methyl3-aminothiophene-2-carboxylate reacted with sodium hydroxide, followed by decarboxylation, and then took part in the reaction with1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carbonyl chloride. Then the product of the last reation reacted with4-methyl-2-pentanone, followed by hydrogenation, penthiopyrad was synthesized. The chemical structures of the key intermediates and penthiopyrad were characterized by1H NMR.