Invalid SMILES

could not parse 'C1=CC(=CC=C1N=NC2C(=NN(C2=O)C3=CC=C(C=C3)S(=O)(=O)', Unclosed branch detected, SMILES may be truncated
C1=CC(=CC=C1N=NC2C(=NN(C2=O)C3=CC=C(C=C3)S(=O)(=O)
                                                 ^