You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name [2-oxo-2-[(1,7,7-trimethyl-2-bicyclo[2.2.1]heptanyl)amino]ethyl] 4,5-dimethoxy-2-nitrobenzoate into its molecular formula.
user
C21H28N2O7
assistant