Using CC(C)Cc1nn(C)c(=O)c2cn(Cc3ccccc3)cc12, O=C=O to produce CC(C)Cc1nn(C)c(=O)c2cn(Cc3ccccc3)c(C(=O)O)c12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.