You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (5R)-5-[3-[(3S)-4-(4-chloro-3-methoxy-5-methylphenyl)-3-methylpiperazin-1-yl]-3-oxopropyl]-5-methylimidazolidine-2,4-dione ?
user
C20H27ClN4O4
assistant