You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (4R,5R)-4-(6,7-dimethoxy-3,4-dihydro-1H-isoquinoline-2-carbonyl)-1-methyl-5-phenylpyrrolidin-2-one into molecular formula.
user
C23H26N2O4
assistant