Using CC(C)(C)OC(=O)N1CCC(C(=O)Cc2cc(Cl)ncc2Br)CC1, C[Mg]Br to produce CC(C)(C)OC(=O)N1CCC(C(C)(O)Cc2cc(Cl)ncc2Br)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.