2,4,5-trifluorobenzyl bromide is an important intermediate in the synthesis of Ensitrelvir (S-217622). Ensitrelvir is the latest oral drug developed by Japan's Shionogi Pharmaceutical Company to treat COVID-19. It is the first orally active, non-covalent, non-peptide SARS-CoV-23CL protease inhibitor.
Preparing 2,4,5-Trifluorobenzyl bromide, involves (a) carrying out esterification reaction on 2,4,5-trifluorobenzyl chloride and carboxylate to prepare 2,4,5-trifluorobenzyl ester, (b) hydrolyzing 2,4,5-trifluorobenzyl ester to prepare 2,4,5-trifluorobenzyl alcohol, and (c) brominating 2,4,5-trifluorobenzyl alcohol to prepare target product.