Using O=C1CCC(=O)N1Br, C=C[C@@H](CCn1cc(-c2cnc3ccccc3c2)c2c(N)ncnc21)NC(=O)OC(C)(C)C to produce C=C[C@@H](CCn1c(Br)c(-c2cnc3ccccc3c2)c2c(N)ncnc21)NC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.