You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named [2-[4-[(2-chlorophenyl)methyl]-3,5-dimethylpyrazol-1-yl]-4-methyl-1,3-thiazol-5-yl]-morpholin-4-ylmethanone by IUPAC nomenclature, provide its molecular formula.
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C21H23ClN4O2S
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