¹³C NMR (176 MHz, CDCl₃) δ 169.25 (s, 1C), 151.37 (s, 1C), 147.85 (s, 1C), 138.57 (s, 1C), 133.93 (s, 1C), 128.46 (s, 1C), 127.19 (s, 1C), 123.98 (s, 1C), 120.09 (s, 1C), 114.22 (s, 1C), 39.41 (s, 1C).