1H NMR (400 MHz, CDCl3) δ 7.27 (d, J = 7.2 Hz, 2H), 7.13 (d, J = 7.4 Hz, 2H), 6.71 (d, J = 15.8 Hz, 1H), 5.97 (d, J = 15.9 Hz, 1H), 2.33 (s, 3H), 1.52 (s, 6H). 13C{1H} NMR (101 MHz, CDCl3) δ 138.00, 132.92, 129.64, 129.34, 129.32, 126.41, 123.52, 34.83 , 27.67, 21.17. GC-MS (m/z) = 185.