You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name methyl 2-[methyl-[2-(4-oxo-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-3-yl)acetyl]amino]benzoate into its molecular formula.
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C21H21N3O4S
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