1H NMR (400 MHz, CDCl3) δ 7.72 (s, 1H), 7.58 (d, J = 8.7 Hz, 4H), 7.52 – 7.42 (m, 3H), 7.00 (d, J = 8.7 Hz, 4H), 3.87 (s, 6H). 13C NMR (101 MHz, CDCl3) δ 159.25, 141.34, 133.85, 129.08, 128.24, 125.33, 125.14, 114.24, 55.36. m/z (GC-MS): 290。