Synthesis of Three Major Metabolites of Pyroxasulfone
In order to meet the needs of toxicological tests for the metabolites of the herbicide Pyroxas-ulfone,the present study designed and optimized the synthetic pathways of the three main metabolites of Pyroxasulfone,M1,M3 and M4.Through a novel synthetic pathway,M1,M3 were successfully synthesized from 4-(chloroMethyl)-5-(difluoroMethoxy)-1-Methyl-3-(trifluoroMethyl)-1 H-pyrazole af-ter a series of reaction steps.M4 was successfully synthesized from Methacrylic acid and 1,1-Dibromo-formaldoxime after a number of reactions.The structure and purity of the metabolites were investigated by NMR-hydrogen spectroscopy(NMR-hydrogen spectrometry),liquid mass spectrometry(LMMS),and high-performance liquid chromatography(HPLC).The structure and purity of the metabolites were determined.After optimizing the synthesis process,the yields of M1,M3 and M4 reached 76.9%,82.5%and 70.1%,respectively.The purity of the synthesized metabolites could reach more than 97%.In the present study,these three Pyroxasulfone metabolites were successfully designed and pre-pared from the perspective of synthetic routes for the first time,which provides an important research basis for the fields of pesticide registration and quality control of pesticide residues.