Using O=C(O)c1cc2c(ncn2-c2ccc(Br)cc2)[nH]1, COCCN to produce COCCNC(=O)c1cc2c(ncn2-c2ccc(Br)cc2)[nH]1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.