Using O=C(CN1C(=O)COc2c(O)cccc21)NC(c1ccccc1)c1ccccc1, COC(=O)CBr to produce COC(=O)COc1cccc2c1OCC(=O)N2CC(=O)NC(c1ccccc1)c1ccccc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.