“…Purified by column chromatography (petroleum ether/EtOAc, 10:1) as a white solid (57.5 mg, 73%); mp 143–145 °C (lit . mp 144–146 °C); IR (KBr) ν 1662 (CO) cm –1 ; 1 H NMR (CDCl 3 , 400 MHz) δ 8.04–7.99 (m, 2H), 7.94–7.91 (m, 2H), 7.51–7.48 (m, 2H), 7.22–7.19 (m, 2H); 13 C{ 1 H} (100 MHz, CDCl 3 ) δ 192.5, 192.0, 166.9 (d, J = 257.0 Hz), 141.8, 132.8 (d, J = 10.0 Hz), 131.2 (d, J = 2.0 Hz), 129.5, 129.34, 129.31, 116.5 (d, J = 22.0 Hz); MS (EI, 70 eV) m / z (%) 262 (4) [M + ], 123 (100).…”