1: 31.58 percent / MoOPH, lithium diisopropylamide / hexane; tetrahydrofuran / 1.5 h / -44 °C 2: 95.15 percent / 30percent aq. HF / acetonitrile / 1.5 h / Ambient temperature View Scheme

1.1: CH3COCl / diethyl ether / 0.5 h / cooling 1.2: 7 percent / acetonitrile; tetrahydrofuran / 45 h / 80 °C 2.1: 92 percent / aq. HCl / tetrahydrofuran; propan-2-ol / 20 °C View Scheme

aniline–terephthalaldehyde resin p-toluenesulfonic acid salt in methanol T=20°C; 32 h;

copper(II) bis(trifluoromethanesulfonate) in dichloromethane T=20°C; 24 h;