1H NMR (400 MHz, CDCl3) δ 7.99 (d, J = 13.6 Hz, 1H), 7.58 (d, J = 13.6 Hz, 1H), 7.48 (d, J = 2.0 Hz, 4H), 1.34 (s, 9H). 13C{1H} NMR (101 MHz, CDCl3) δ 156.08, 138.98, 136.32, 129.03, 127.17, 126.35, 35.05, 30.94. GC-MS (m/z): 203.