You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named N-(4-chloro-2,5-dimethoxyphenyl)-4-(3,4-dimethyl-N-methylsulfonylanilino)butanamide is given. What is its corresponding molecular formula?
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C21H27ClN2O5S
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