Thionyl chloride (0.61 mL) was slowly added to methanol (20 mL) and the reaction mixture was stirred for 5 minutes under ice bath cooling. Subsequently, 3,4,5-trifluorobenzoic acid (1.00 g) was added in batches under the same cooling conditions, and the temperature was gradually raised to 60 °C after the addition was completed. The reaction was kept at this temperature with continuous stirring for 5 hours. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently concentrated under reduced pressure to remove the solvent. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane mixed solvent) to afford the target product methyl 3,4,5-trifluorobenzoate (712 mg) as a colorless oil.
