You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 3,4-dimethoxy-N-[2-oxo-2-[(2Z)-2-[(2,4,5-trimethoxyphenyl)methylidene]hydrazinyl]ethyl]benzamide ?
user
C21H25N3O7
assistant