Using CCC(C(=O)CC#N)(c1ccc(Cl)cc1)n1ccc2c(NS(C)(=O)=O)cccc21, BrCCBr to produce CCC(C1=C(C#N)CCO1)(c1ccc(Cl)cc1)n1ccc2c(NS(C)(=O)=O)cccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.