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 2-(2-chloro-4,6-dimethylphenoxy)-N-[4-(4-methylsulfonylpiperazin-1-yl)phenyl]acetamide using the IUPAC nomenclature.
user
C21H26ClN3O4S
assistant