Using O=S(=O)(CCO)c1cc2c(Nc3cccc(Br)c3)ncnc2cn1 to produce C=CS(=O)(=O)c1cc2c(Nc3cccc(Br)c3)ncnc2cn1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.