Using O=C1CCc2c(-c3ccccc3)[nH]c3c(O)ccc1c23, COC(=O)CBr to produce COC(=O)COc1ccc2c3c(c(-c4ccccc4)[nH]c13)CCC2=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.