Using O=C(N(c1ccccc1)c1ccccc1)N(c1ccccc1)c1ccccc1, N to produce N=C(N(c1ccccc1)c1ccccc1)N(c1ccccc1)c1ccccc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.