You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl 4-[2-[[3-(3,5-dimethylphenyl)-4-oxo-6,7-dihydrothieno[3,2-d]pyrimidin-2-yl]sulfanyl]acetyl]piperazine-1-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H28N4O4S2
assistant