Using CC(C)(O)Cn1cnc2c(N)nc3cc(C=CS(C)(=O)=O)ccc3c21 to produce CC(C)(O)Cn1cnc2c(N)nc3cc(CCS(C)(=O)=O)ccc3c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.