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 (4aS,7aS)-4-(4-bromophenyl)-1-(3-methylbutyl)-6,6-dioxo-4a,5,7,7a-tetrahydro-2H-thieno[3,4-b]pyrazin-3-one .
user
C17H23BrN2O3S
assistant