Using C=CCBr, CCC(=O)C1=C(O)CC(c2ccc3c(c2)NC(=O)CO3)CC1=O to produce C=CCN1C(=O)COc2ccc(C3CC(=O)C(C(=O)CC)=C(O)C3)cc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.