You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-[(2,6-dichlorophenyl)methyl]-4,7,8-trimethyl-6-propan-2-ylpurino[7,8-a]imidazole-1,3-dione .
user
C20H21Cl2N5O2
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