You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (3-chloro-1-benzothiophen-2-yl)-[(1R)-6,7-dimethoxy-1-methyl-3,4-dihydro-1H-isoquinolin-2-yl]methanone ?
user
C21H20ClNO3S
assistant