Using COCCBr, Cn1nc(-c2cc(F)c(O)c(Br)c2)c2cnc(N)nc21 to produce COCCOc1c(F)cc(-c2nn(C)c3nc(N)ncc23)cc1Br, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.