¹³C NMR (176 MHz, CDCl₃) δ 162.75 (s, 1C), 151.32 (s, 1C), 149.46 (s, 1C), 148.40 (s, 1C), 148.39 (s, 1C), 138.43 (s, 1C), 137.70 (s, 1C), 126.87 (s, 1C), 122.57 (s, 1C), 120.01 (s, 1C), 114.06 (s, 1C).