Using O=C1CCC(=O)N1Br, CC1=C(C#N)C(c2ccccc2Cl)c2cn(C(=O)OC(C)(C)C)nc2N1 to produce CC(C)(C)OC(=O)n1cc2c(n1)NC(CBr)=C(C#N)C2c1ccccc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.