Using CC(C)(C)OC(=O)CCCBr, COC(=O)Cn1nc(-c2ccc(Cl)cc2)[nH]c1=O to produce COC(=O)Cn1nc(-c2ccc(Cl)cc2)n(CCCC(=O)OC(C)(C)C)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.