You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 1-[2-(3-chloro-4-methylsulfonylthiophene-2-carbonyl)pyrazolidin-1-yl]-3-(2,5-dimethoxyphenyl)prop-2-en-1-one by IUPAC nomenclature, provide its molecular formula.
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C20H21ClN2O6S2
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