1H NMR (400 MHz, CDCl3) δ 7.20 (d, J = 7.7 Hz, 2H), 6.85 (d, J = 7.7 Hz, 2H), 5.04 (d, J = 4.3 Hz, 1H), 3.98 – 3.90 (m, 2H), 3.88 – 3.84 (m, 2H), 3.79 (s, 3H), 2.92 (d, J = 3.5 Hz, 2H). 13C NMR (101 MHz, CDCl3) δ 158.30, 130.55, 128.12, 113.72, 104.75, 64.90, 55.14, 39.79.