Using COC(=O)CBr, Cc1sc2c(Br)c3ccccc3c(C3=CC(Br)([N+](=O)[O-])C(O)C=C3)c2c1C to produce Cc1sc2c(Br)c3ccccc3c(C3=CC(Br)([N+](=O)[O-])C(OCC(=O)O)C=C3)c2c1C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.