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 methyl 4-[[4-(8-methoxy-2-methyl-2,3-dihydroimidazo[1,2-a]pyridin-3-yl)pyrimidin-2-yl]amino]benzoate into molecular formula.
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C21H21N5O3
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