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For the molecule named 3-(3-bromophenyl)-N-[1-[(2,4-dichlorophenyl)methyl]-5-methylpyrazol-3-yl]-4,5-dihydro-1,2-oxazole-5-carboxamide by IUPAC nomenclature, provide its molecular formula.
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C21H17BrCl2N4O2
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