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 1-[3-[(6-acetyl-2,3-dihydro-1,4-benzoxazin-4-yl)sulfonyl]-4-methoxyphenyl]pyrrolidin-2-one ?
user
C21H22N2O6S
assistant