You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as N-[4-[4-[(4-fluorophenyl)methyl]piperazine-1-carbonyl]-2-(trifluoromethoxy)phenyl]ethanesulfonamide using the IUPAC nomenclature.
user
C21H23F4N3O4S
assistant