Using COCCBr, CC(C)(O)c1nnc2ccc(-c3c(-c4ccc(F)cc4F)nc4occn34)nn12 to produce COCCOC(C)(C)c1nnc2ccc(-c3c(-c4ccc(F)cc4F)nc4occn34)nn12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.