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-[(5'-methoxy-2'-oxo-3-propanoylspiro[1,3-thiazolidine-2,3'-indole]-1'-yl)methyl]benzonitrile .
user
C22H21N3O3S
assistant