¹H NMR (400 MHz, CDCl₃) δ 10.34 (s, 1H), 9.28 (d, J = 9.2 Hz, 1H), 7.85 (d, J = 7.0 Hz, 1H), 7.51 (d, J = 7.0 Hz, 1H), 7.42 (d, J = 7.8 Hz, 2H), 7.35 (d, J = 9.4 Hz, 1H), 7.31 (s, 1H), 7.04 (d, J = 7.8 Hz, 2H), 4.14 (q, J = 6.8 Hz, 2H), 4.00 (q, J = 6.7 Hz, 2H), 1.49 (t, J = 6.7 Hz, 3H), 1.41 (t, J = 6.7 Hz, 3H). ¹³C NMR (101 MHz, CDCl₃) δ 193.54, 158.88, 157.44, 145.93, 134.22, 133.89, 132.31, 130.78, 130.33, 126.72, 126.54, 126.32, 120.81, 114.49, 106.55, 63.59, 63.38, 14.90, 14.66.