Using Cc1nc2sc(C(=O)OC(C)(C)C)c(N)c2c(C)c1O, ClCCBr to produce Cc1nc2sc(C(=O)OC(C)(C)C)c(N)c2c(C)c1OCCCl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.