1H NMR (400 MHz, CDCl3) δ 8.65 (s, 1H), 7.45 (d, J = 7.6 Hz, 2H), 7.35 (d, J = 7.5 Hz, 2H); 13C NMR (101 MHz, CDCl3) δ 160.0 (s), 135.9 (s), 130.3 (s), 129.3 (s), 122.9 (s), 116.0 (s). HRMS (EI): calculated for C9H5N2O3Cl: 223.9982; found: 223.9983.