You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-[4-(2-chloro-5-methylsulfanylbenzoyl)piperazin-1-yl]-N-[2-(trifluoromethyl)phenyl]acetamide .
user
C21H21ClF3N3O2S
assistant