You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule N-(2-bromo-4-methylphenyl)-2-[6-(4-methoxyphenyl)imidazo[2,1-b][1,3]thiazol-3-yl]acetamide into molecular formula.
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C21H18BrN3O2S
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