Using Nc1nc(Nc2cc(Cl)cc(Cl)c2)n[nH]1, O=Cc1ccc(Cl)cn1 to produce Clc1ccc(CNc2nc(Nc3cc(Cl)cc(Cl)c3)n[nH]2)nc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.