How is 4-Chloro-3,5-difluorobenzoic acid (CAS: 1160573-19-2) typically synthesized?

4-Chloro-3,5-difluorobenzoic acid can be synthesized via the Friedel-Crafts alkylation of 3,5-difluorobenzoic acid with chlorine in the presence of a Lewis acid catalyst such as aluminum chloride. The reaction yields a high purity product with good yield. Other methods include direct substitution of fluorinated benzene derivatives with chlorinating agents under appropriate conditions.