PURPOSE: To obtain the title compound useful as an intermediate for synthesizing medicines and pesticides in high yield at low cost through a few processes by nuclear chlorination of a benzotrichloride followed by partial hydrolysis, fluorinated and finally hydrolysis.

CONSTITUTION: Firstly, a benzotrichloride compound of formula I (X is H, Cl or F; (m) is 0 - 3) is allowed to react with a chlorinating agent (e.g. chlorine gas) in the presence of a catalyst (e.g. ferric chloride) into a compound of formula II (Y is Cl or F). Second, this compound is hydrolyzed with water into a compound of formula III, which is then allowed to react with an alkali metal fluoride (e.g. KF) in the presence of a phase-transfer catalyst (e.g. tetramethylammonium chloride) to give a compound of formula IV. Finally, this compound is hydrolyzed, thus obtaining the objective compound of formula V. The present compound can be produced from inexpensive, readily available raw materials and there is no concern about such problems on the processes as the toxicity of the intermediate products and catalyst deactivation.