You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-[2-(2,3-dihydro-1,4-benzodioxine-3-carbonyl)hydrazinyl]-2-oxoethyl] 3-chloro-4-ethoxy-5-methoxybenzoate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H21ClN2O8
assistant