You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)-N-[2-(4-fluorophenyl)ethyl]-2-oxoacetamide .
user
C21H23FN2O4
assistant