Patent ID: 8362261

Claim:
A process for preparing a pyridyl substituted pyrazole derivative of formula (I) in which R 1 is alkoxy, hydroxyl, aryloxy, alkylaryloxy, alkyl, cycloalkyl, or halogen, R 2 is hydroxyl, alkoxy, arylalkoxy, alkylthio, chlorine, bromine, fluorine, iodine, O—(C═O)alkyl, O—(C═O)O-alkyl, OSO 2 alkyl, OSO 2 Ph, OSO 2 -haloalkyl, or OSO 2 -aryl, and R 3 is halogen, CN, NO 2 , alkyl, cycloalkyl, haloalkyl, halocycloalkyl, alkoxy, haloalkoxy, alkylamino, dialkylamino, or cycloalkylamino, comprising (A) reacting an acetylketone of formula (II) in which R 4 is a protecting group selected from the group consisting of (C 1 -C 6 )-alkyl, aryl, benzyl, tetrahydropyran, (C═O)-alkyl, (C═O)-Oalkyl, and Si(alkyl) 3 , and X is halogen, with a hydrazinopyridine of formula (III) in which R 3 is defined as above, in the presence of a solvent, to give a 1-pyridyl-substituted dihydro-1H-pyrazole of formula (IV) in which X, R 3 , and R 4 are each as defined above; (B) optionally without isolating, in the presence of a solvent, reacting the compound of formula (IV) by eliminating water, to give a 1-pyridyl-substituted trihalomethylpyrazole of formula (V) in which X, R 3 , and R 4 are each as defined above; (C) reacting the compound of formula (V) under an acidic or basic condition, optionally in the presence of a catalyst, to give a pyrazolecarboxylic acid of formula (VI) in which R 3 , and R 4 are each as defined above; (D) removing the protecting group R 4 to give a hydroxymethylpyrazole acid of formula (VII) in which R 3 is as defined above; (E) reacting the compound of formula (VII) with a halogenating agent, in the presence of a solvent, to give an acid halide; and optionally further reacting the halide with an alcohol to give the compound of formula (I).