PURPOSE: To industrially obtain in a single step in high yield the title compound useful as an intermediate for medicines by reaction of, as the starting material, an industrially readily available 3,4-difluorobenzoic acid alkali metal salt with a halogenating agent.

CONSTITUTION: The objective compound (e.g. 2-chloro-4,5-difluorobenzoic acid) can be obtained by reaction between (A) a 3,4-difluorobenzoic acid alkali metal salt readily producible by mixing 3,4-difluorobenzoic acid with an alkali hydroxide and (B) a halogenating agent (e.g. gaseous chlorine). The 3,4-difluorobenzoic acid as the starting material can be easily obtained by hydrolysis of industrially readily available 4-difluorobenzonitrile with an acid. The present compound is useful as an intermediate for fluorine-contg. quinolonecarboxylic acid- or fluorine-contg. pyridonecarboxylic acid-based synthetic antibacterial agents. The present method will accomplish high selectivity and high yield.