Using ClC(Cl)(Cl)Cl, CC(C)(C)OC(=O)N1CCc2c(O)ncnc2C1 to produce CC(C)(C)OC(=O)N1CCc2c(Cl)ncnc2C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.