Process for preparing aryl-substituted pyrazoles

A process for preparing an aryl-substituted pyrazole of general formula (I)

• in which
• R1 is hydroxyl, alkoxy, aryloxy or halogen,
• R2 is hydroxyl, alkoxy, arylalkoxy, alkylthio, halogen, O—(C═O)alkyl, O—(C═O)O-alkyl, (C═O)haloalkyl, OSO2alkyl, OSO2-haloalkyl or OSO2-aryl,
• R3 is halogen, CN, NO2, alkyl, cycloalkyl, haloalkyl, halocycloalkyl, alkoxy, haloalkoxy, alkylamino, dialkylamino or cycloalkylamino,
• Z is CH or N,
• characterized in that
• (A) an alkoxyenone or an enaminoketone of formula (II)
• in which
• R4 is H, alkyl, arylalkyl, —(C═O)alkyl, (C═O)haloalkyl, —(C═O)O-alkyl, SO2alkyl, SO2-haloalkyl or SO2-aryl,
• X is, chlorine, bromine or iodine,
• R5 is alkoxy, dialkylamino, cycloalkylamino or thioalkyl, or is cycloalkyl which may optionally contain 1-3 heteroatoms from the group of O, N or S,
• is reacted with an arylhydrazine of the formula (III)
• in which
• R3 is halogen, CN, NO2, alkyl, cycloalkyl, haloalkyl, halocycloalkyl, alkoxy, haloalkoxy, alkylamino, dialkylamino or cycloalkylamino,
• Z is CH or N,
• to give a 1-aryl-substituted dihydro-1H-pyrazole of the formula (IV)
• in which X, R3, R4 and Z are each as defined above,
• (B) the latter is optionally converted further, without preceding isolation, with elimination of water, to a 1-aryl-substituted trihalomethylpyrazole of the formula (V)
• in which X, R3, R4 and Z are each as defined above,
• (C) the compound of the general formula (V) is converted with addition of HC1, H2SO4 or a base, to a pyrazolecarboxylic acid of the formula (VI)
• in which R3, R4 and Z are each as defined above,
• (D) the latter is converted, after detaching the R4 group, to a hydroxymethylpyrazole acid of the formula (VII)
• in which R3 and Z are as defined above, and
• (E) the latter is converted to a compound of the formula (I)