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 (4S)-1-ethyl-4-[4-[(R)-(1-methylimidazol-2-yl)-phenylmethyl]piperazine-1-carbonyl]pyrrolidin-2-one ?
user
C22H29N5O2
assistant