PRODUCTION OF 4-HALOGENO-3-TRIFLUOROMETHYLPHENOXYBUTANOIC ACID ESTERS

摘要

PROBLEM TO BE SOLVED: To obtain the subject compound useful as an intermediate for synthesizing amide herbicides by reacting a 2-bromobutanoic acid ester with a 4- halogeno-3-trifluoromethylphenol in the presence of a base in a specific solvent. SOLUTION: This compound of formula III is obtained by reacting a 2- bromobutanoic acid ester of formula I (R is a 1-4C alkyl) (e.g. methyl 2- bromoturanoate) with a 4-halogeno-3-trifluoromethylphenol of formula II (X is a halogen) (e.g. 2-fluoro-5-hydroxybenzotrifluoride) in the presence of a base (e.g. potassium carbonate) in acetonitrile or methylisobutylketone as a solvent. The addition of 0.5-2 times volume of water to the solvent after the finish of the reaction gives the objective compound in a further enhanced yield.