pyridine in dichloromethane T=24°C; 288 h;

ammonium cerium(IV) nitrate; iodine; sodium hydrogencarbonate in acetonitrile 96 h; Heating / reflux;

1: 73 percent / sodium hydride (60 percent) / tetrahydrofuran / 1.5 h / Ambient temperature 2: 1.) pyridine, DMF, copper powder, 4-dimethylaminopyridine / 1.) < -70 to 115 deg C; sealed tube, 2.) 8 h, 60 deg C; sealed tube was opened 3: methanolic HCl (2 percent) / 2 h / Ambient temperature View Scheme