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 3-[4-(4-bromo-2-chlorophenyl)sulfonylpiperazin-1-yl]-N-cyclopropylquinoxalin-2-amine .
user
C21H21BrClN5O2S
assistant