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-(2,3-dihydro-1H-inden-5-yloxy)-1-[4-(4-fluorophenyl)sulfonylpiperazin-1-yl]ethanone .
user
C21H23FN2O4S
assistant