Using O=C1CCC(=O)N1Br, CCOC(=O)c1cc2ccsc2n1C(=O)OC(C)(C)C to produce CCOC(=O)c1cc2cc(Br)sc2n1C(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.