You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[5-(4-ethoxyphenyl)-4-oxothieno[2,3-d]pyrimidin-3-yl]-N-(4-ethylphenyl)acetamide by IUPAC nomenclature, provide its molecular formula.
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C24H23N3O3S
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