Using O=CO, COc1cc2ncnc(Nc3cccc(Br)c3)c2c(N)c1OC to produce COc1cc2ncnc3c2c(c1OC)N=CN3c1cccc(Br)c1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.