You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance methyl 2-[[2-(6-bromo-4-oxoquinazolin-3-yl)acetyl]amino]-6-methyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate .
user
C21H20BrN3O4S
assistant