“…The mixture was stirred at 40 °C under N 2 atmosphere for 5 h until TLC monitoring indicated the disappearance of compound 1 . The solvent was removed in vacuo, and the crude reaction mixture was purified by silica gel column chromatography using PE/CH 2 Cl 2 (2/1, v / v ) as eluent to give 2 [ 58 ] in 83% yield (391.0 mg). 1 H-NMR (400 MHz, CDCl 3 ) δ 7.34 (d, J = 8.7 Hz, 2H), 7.31-7.27 (m, 4H), 7.12–7.06 (m, 6H), 6.98 (d, J = 8.7 Hz, 2H), 0.27 (s, 9H).…”