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 3-methoxy-N-[[5-(1-oxo-5,6,7,8-tetrahydro-2H-isoquinolin-4-yl)furan-2-yl]methyl]benzenesulfonamide is given. What is its corresponding molecular formula?
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C21H22N2O5S
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