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 2-[2-chloro-5-(2,5-dioxo-3-propan-2-ylidenepyrrolidin-1-yl)anilino]-N-piperidin-1-ylpropanamide is given. What is its corresponding molecular formula?
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C21H27ClN4O3
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