Using COc1ccc(Oc2c(Cl)cc(C=C3SC(=O)NC3=O)cc2Cl)cc1 to produce COc1ccc(Oc2c(Cl)cc(CC3SC(=O)NC3=O)cc2Cl)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.