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-[(2R)-1-oxo-1-[[(2S)-1-oxo-1-(2-oxoethylamino)propan-2-yl]amino]-3-phenylpropan-2-yl]benzamide .
user
C21H23N3O4
assistant