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 (2R)-1'-(4,6-dimethyl-2-oxo-1H-pyridine-3-carbonyl)spiro[3,4-dihydro-1,4-benzoxazepine-2,3'-piperidine]-5-one ?
user
C21H23N3O4
assistant