¹³C NMR (176 MHz, CDCl₃) δ 164.33 (s, 1C), 149.94 (s, 1C), 148.17 (s, 1C), 138.36 (s, 1C), 137.57 (s, 1C), 128.84 (s, 1C), 128.00 (s, 1C), 127.61 (s, 1C), 126.36 (s, 1C), 122.54 (s, 1C), 43.63 (s, 1C).