1H NMR (400 MHz, CDCl3) δ 8.59 (s, 1H), 7.29 – 7.24 (m, 4H), 2.40 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 159.7 (s), 139.7 (s), 129.6 (s), 128.7 (s), 121.4 (s), 116.8 (s), 21.2 (s). HRMS (EI): calculated for C10H8N2O3: 204.0535; found: 204.0531.