Using O=C(Nc1cccc2c(Cl)ccnc12)c1c(Cl)cccc1Cl, COCCO to produce COCCOc1ccnc2c(NC(=O)c3c(Cl)cccc3Cl)cccc12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.