¹H NMR (700 MHz, CDCl₃) δ 7.93 (s, 2H), 7.58 (s, 1H), 7.43 (t, J = 7.4 Hz, 2H), 7.38 (t, J = 7.6 Hz, 2H), 7.33 (d, J = 7.6 Hz, 2H), 3.78 (s, 2H).