Using O=C1CCC(=O)N1Br, CCOC(=O)c1[nH]c2cc(C)sc2c1C#N to produce CCOC(=O)c1[nH]c2c(Br)c(C)sc2c1C#N, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.