¹³C NMR (176 MHz, CDCl₃) δ 169.10 (s, 1C), 142.86 (s, 1C), 134.98 (s, 1C), 133.49 (s, 1C), 129.81 (s, 1C), 129.18 (s, 1C), 127.57 (s, 1C), 125.11 (s, 1C), 123.77 (s, 1C), 119.97 (s, 1C), 119.05 (s, 1C), 45.58 (s, 1C), 44.50 (s, 1C).