You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-O-methyl 2-O-[2-(2-methyl-6-propan-2-ylanilino)-2-oxoethyl] benzene-1,2-dicarboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23NO5
assistant