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 N-[4-[2-[6,7-dimethoxy-2-[(4-nitrophenyl)methyl]-4-oxospiro[3H-isoquinoline-1,4'-piperidine]-1'-yl]ethyl]phenyl]methanesulfonamide .
user
C31H36N4O7S
assistant