Using FC(F)(F)c1cccc(-c2ccnc3cncn23)c1, O=C1CCC(=O)N1Cl to produce FC(F)(F)c1cccc(-c2ccnc3c(Cl)ncn23)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.