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-[(2S)-1-[4-(3-chlorophenyl)piperazin-1-yl]-1-oxopropan-2-yl]-1,2-benzothiazol-3-one is given. What is its corresponding molecular formula?
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C20H20ClN3O2S
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