synthesis of 2,4,5-trifluorophenylacetic acid: A 100 mL flask was charged 10.0 g of 2,4,5-trifluoromandelic acid, 23.9 g of H3PO3 (6 eq.), 0.73 g of Nal (0.1 eq.) and 0.47 g (0.10 eq.) of MSA. The obtained mixture was stirred at 95-105°C for 24 hrs. Once the conversion is completed (by HPLC; conversion > 99%, typically achieved after 24 hours), the mixture is cooled to room temperature, and 20 mL of methyl tert-butyl ether were added and then 20 mL of water where added. The obtained mixture was stirred for 5 min, then the organic layers were separated. Then 10 mL of methyl tert-butyl ether was added to the aqueous layers, stirred for 5 min, then the phase were separated. The organic layers were combined. The combined organic layers were concentrated under vacuum at 35°C, to provide crude 2,4,5-trifluorophenylacetic acid(TFPAA). To the obtained crude TFPAA was recrystallized from toluene, to obtain TFPAA, as a white crystals, 6.4 g, molar yield 69.5%, chemical purity of HPLC 99.47% A/A%