Using O=C1CCC(=O)N1Br, CCCn1nnn(-c2cc(OC(C)C)c(C)cc2Cl)c1=O to produce CCCn1nnn(-c2cc(OC(C)C)c(CBr)cc2Cl)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.