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 [1-(4-chlorophenyl)sulfonylpyrrolidin-2-yl]-[4-(2-nitrophenyl)sulfanylpyrazol-1-yl]methanone .
user
C20H17ClN4O5S2
assistant