| Profoxydim,which is a highly effective,safe and selective acetyl-Co A carboxylase inhibitor(ACCase inhibitor),is a cyclohexenone herbicide.It is used for weeding in paddy fields and the herbicidal effect is remarkable.Based on the synthetic method of profoxydim reported in the literature,this project comprehensively synthesized cyclopentanone and rationally optimized the synthetic process.The profoxydim was split into two parts for synthesis,namely the triketone moiety 2-butyryl-3-hydroxy-5-(tetrahydrothiopyran-3-yl)cyclohex-2-en-1-one and the side chain moiety O-[2-(4-chlorophenoxy)propyl]hydroxylamine,and then the two parts were joined to form profoxydim.The synthesis of the triketone moiety was carried out by using acrolein and hydrogen sulfide as starting materials,through adding,Aidol condensation cyclizing,eliminating the three-step reaction to obtain the intermediate3-formyl-5,6-dihydrothiopyran,and then hydrogenating to obtain an intermediate of3-formyltetrahydrothiopyran,which was further subjected to condensation,Michael addition,Claisen condensation cyclization,esterification,rearrangement and decarboxylation to give a triketone moiety.The side chain moiety was synthesized by using acetone oxime and propylene oxide or propylene carbonate as starting materials,and was obtained by a four-step reaction of ring opening,esterification,condensation and hydrolysis.The final triketone moiety and the side chain moiety were condensed to give the final product,profoxydim.Some reactions were monitored by TLC,gas chromatography or liquid chromatography detection methods.The synthesized profoxydim and key intermediates were characterized by ~1H NMR,LC-MS,and the structures were confirmed. |
