You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as methyl 2-[(2R)-3-oxo-1-[2-oxo-2-(2-phenylsulfanylanilino)ethyl]piperazin-2-yl]acetate using the IUPAC nomenclature.
user
C21H23N3O4S
assistant