Using Cn1cc(Br)cc(Nc2ccc(N3CCN(C(=O)OC(C)(C)C)CC3)cn2)c1=O to produce Cn1cc(Br)cc(Nc2ccc(N3CCNCC3)cn2)c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.