You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[2-[(dimethylamino)methyl]-4-oxo-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-3-yl]-N-(4-nitrophenyl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23N5O4S
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