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-[(2-chlorophenyl)methyl]-N-methyl-5-methylsulfonyl-4-piperidin-3-ylpyrimidin-2-amine is given. What is its corresponding molecular formula?
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C18H23ClN4O2S
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