¹H NMR (400 MHz, CDCl₃) δ 8.60 (s, 1H), 7.34 (t, J = 7.6, J = 7.2 Hz, 1H), 7.28 (s, 1H), 7.18 (d, J = 7.9 Hz, 2H), 2.39 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 159.8 (s), 138.8 (s), 130.3 (s), 129.4 (s), 128.8 (s), 125.9 (s), 124.3 (s), 116.9 (s), 21,3 (s). HRMS (EI): calculated for C₁₀H₈N₂O₃: 204.0535; found: 204.0532.