The present invention relates to a process for preparing 1,3-substituted pyrazole compounds of the formula Iin whichX is especially a CX1X2X3 group in whichX1, X2 and X3 are each independently especially hydrogen, fluorine or chlorine,R1 is C1-C4-alkyl or cyclopropyl, and R2 is hydrogen, CN or a CO2R2a group in whichR2a is especially C1-C6-alkyl,comprising the following steps:i) reacting a compound of the formula II with a hydrazone of the formula IIIwhere the variables X and R2 in formula II are each as defined for formula I, Y is oxygen, an NRy1 group or an [NRy2Ry3]+Z− group, R3 is OR3a or an NR3bR3c group, and where the variable R1 in formula III is as defined for formula I, R4 and R5 are each independently hydrogen, C1-C6-alkyl, optionally substituted phenyl, where at least one of the R4 and R5 radicals is different from hydrogen, and where R4 and R5 together with the carbon atom to which they are bonded may also be a 5- to 10-membered saturated carbocycle ii) treating the reaction product obtained with an acid in the presence of water.
