¹H NMR (400 MHz, CDCl₃) δ 9.79 (s, 1H), 7.42 (dq, J = 10.1, 2.9 Hz, 4H), 7.30 (dd, J = 5.8, 2.7 Hz, 1H), 7.26 – 7.18 (m, 6H). ¹³C NMR (101 MHz, CDCl₃) δ 193.82, 150.06, 141.75, 133.98, 133.30, 130.69, 130.17, 129.29, 128.80, 128.45, 128.26.