You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named ethyl 2-[[2-(1-tert-butyl-2,5-dimethylpyrrol-3-yl)-2-oxoethyl]amino]benzoate is given. What is its corresponding molecular formula?
user
C21H28N2O3
assistant