¹H NMR (400 MHz, CDCl₃): δ 7.76 (d, J = 7.7 Hz, 2H), 7.53 (t, J = 7.3 Hz, 1H), 7.43 (t, J = 7.5 Hz, 2H), 5.82 (s, 1H), 5.58 (s, 1H), 2.46 (t, J = 7.6 Hz, 2H), 1.62–1.47 (m, 2H), 0.97 (t, J = 7.3 Hz, 3H). ¹³C NMR (100 MHz, CDCl₃): δ 198.5, 148.2, 137.9, 132.1, 129.5, 128.1, 125.3, 34.3, 21.3, 13.8