Abstract: Processes for producing optically active ester derivatives are disclosed. According to the present invention an optically active aryloxyphenoxy propionate derivative is produced by reacting a chlorinated heterocyclic aromatic compound with (2R)-2-(4-hydroxyphenoxy)propionic acid tetrahydrofurfuryl ester in an anhydrous solvent in the presence of a base. According to the present invention, an optically active propionate derivative of the formula [I] ##STR1## (wherein R represents hydrogen or 3-chloro-5-trifluoromethyl-2-pyridyl group) is produced by reacting a corresponding optically active methyl propionate derivative with tetrahydrofurfuryl alcohol, or by reacting a corresponding optically active propionic acid derivative with tetrahydrofurfuryl alcohol, or by reacting (2S)-tetrahydrofurfuryl 2-chloropropionate with a corresponding phenol derivative in specific conditions.

Abstract: A process of producing 2-(4'-hydroxyphenoxy)-3-chloro-5-trifluoromethylpyridine with high efficiency, which is suited for industrial scale production is disclosed. In the process of the present invention, hydroquinone, a dehydrohalogenating agent in the amount of 0.10-0.70 equivalent of the hydroquinone, and a mixed solvent of a polar aprotic solvent and an aromatic hydrocarbon solvent are mixed. The resulting mixture is then heated to reflux at atmospheric pressure to dehydrate the mixture. Then 2,3-dichloro-5-trifluoromethylpyridine in the amount of 0.20-0.95 equivalent of the dehydrohalogenating agent is added to the mixture, and the resulting mixture is allowed to react at a temperature of 100.degree.-170.degree. C.