¹H NMR (700 MHz, CDCl₃) δ 7.99 (s, 1H), 7.90 (t, J = 1.9 Hz, 2H), 7.83 (q, J = 3.1 Hz, 3H), 7.54 (m, J = 3.4 Hz, 3H), 7.46 (t, J = 7.8 Hz, 3H), 7.26 (m, J = 2.0 Hz, 2H), 7.20 (t, J = 8.0 Hz, 2H).