PURPOSE: To produce the subject compound useful as an intermediate for agricul tural chemical by using a 3-(5-bromo-2,4-dihalogenated phenyl)-pyrazole as a starting substance by one-stage reaction or through an ester derivative by a short process advantageously.
CONSTITUTION: A compound of a pyrazole of formula II obtained by brominating a compound of formula VI (R1 is alkyl; R2 is haloalkyl; X1 to X3 are halogen) is used as a starting material. (1) The compound of formula II is reacted with CO by using a metal catalyst of group VIII of the periodic table (e.g. Pd chloride) and a ligand (e.g. trimethylphosphine or pyridine) in the presence of a base and water to give a 2,4-dihalogeno-5-(pyrazol-3-yl)benzoic acid derivative of formula I (e.g. compound of formula IX). (2) The compound of formula II is reacted with a compound of formula III (R3 is alkyl) to give a compound of formula IV, which is hydrolyzed to give the compound of formula I. Or (3) the compound of formula II is reacted with a compound of formula V to give a compound of formula VI, which is converted into a haloform to give the compound of formula I.
NAKAO ISAMI
HAMAGUCHI HIROSHI
