| 摘要 |
The present invention relates to a method for preparing 1-phenylpyrrazolin-3-carboxylic acid derivatives of the general formula (III), wherein said method comprises reacting hydrazones of the general formula (I) with olefins of the general formula (II) using a base as a catalyst. In the above-mentioned formulae, Ph is an optionally substituted phenyl, R1 is hydrogen or alkyl, R2 and R3 are independently hydrogen, halogen, cyano, an optionally substituted organic residue or R2 and R3 form together with the carbon atom bearing them a saturated or partially saturated cyclic compound comprising 5 or 6 atoms. X is amino, hydroxy, alkoxy, cycloalkoxy, alkylamino, dialkylamino, alkyloxyalkyloxy, trialkylsilyloxy or trialkylsilylmethyloxy and Y is chlorine or bromine. This reaction is carried out in a two-phase system comprising an organic phase and an aqueous phase using a sterically hindered amine and an optional other base. The 1-phenylpyrrazolin-3-carboxylic acid derivatives of the present invention can be used as phyto-protective agents, i.e. as agents for protecting useful crops in agriculture or silviculture against undesired effects due to the application of herbicides.
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