Using CC(=O)OC(C)(C)C, CSc1nc(Cl)c(CBr)c(-c2ccc(F)cc2F)n1 to produce CSc1nc(Cl)c(CCC(=O)OC(C)(C)C)c(-c2ccc(F)cc2F)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.