You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 11-[(6-methyl-4-oxopyrido[1,2-a]pyrimidin-2-yl)methyl]-7,11-diazatricyclo[7.3.1.02,7]trideca-2,4-dien-6-one into its molecular formula.
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C21H22N4O2
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