You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 4-[[4-[(E)-2-(4-hydroxy-5-nitro-6-oxo-1H-pyrimidin-2-yl)ethenyl]-2-methoxyphenoxy]methyl]benzonitrile ?
user
C21H16N4O6
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