potassium carbonate in N,N-dimethyl acetamide T=135°C; 16 h;

aluminium trichloride in dichloromethane 1.) 30 min, 0 deg C, 2.) 1 h, RT;

1: 1.) 30 percent KOH / 1.) THF, EtOH, 18 h, 2.) H2O, acetic acid, reflux, 1 h 2: 6 N HCl / hexane / 1 h / Heating 3: 10 g / K2CO3 / N,N-dimethyl-acetamide / 16 h / 135 °C View Scheme