Using O=C(CCCCl)Nc1nc(NC(=O)CCCCl)nc(NC(=O)CCCCl)n1 to produce O=C1CCCN1c1nc(N2CCCC2=O)nc(N2CCCC2=O)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.