“…The crude product was chromatographed on silica (petroleum ether/EtOAc) to give a white solid, 83% (74.3 mg). dl- 7k : 1 H NMR (400 MHz, DMSO) δ 7.85 (d, J = 8.4 Hz, 4H), 7.38 (d, J = 8.3 Hz, 4H), 5.52 (dd, J = 3.2, 1.5 Hz, 2H), 4.68 (d, J = 4.3 Hz, 2H), 2.53 (s, 6H).…”