Using COC(=O)Cc1cn(Cc2ccc(Cl)c(Cl)c2)c2ncccc12 to produce O=C(O)Cc1cn(Cc2ccc(Cl)c(Cl)c2)c2ncccc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.