Using C=COCCONC(=O)c1cc2ocnc2c(F)c1Nc1ccc(Br)cc1Cl to produce O=C(NOCCO)c1cc2ocnc2c(F)c1Nc1ccc(Br)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.