You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named propyl 2-chloro-5-[[2-[(5E)-5-[(4-hydroxy-3-methoxy-5-nitrophenyl)methylidene]-2,4-dioxo-1,3-thiazolidin-3-yl]acetyl]amino]benzoate by IUPAC nomenclature, provide its molecular formula.
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C23H20ClN3O9S
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