1: 64 percent / tetrabutylammonium bromide / dimethylformamide / 24 h / 170 °C 2: 74 percent / pyridine / CH2Cl2 / 48 h / Ambient temperature 3: 14 percent / NaH (60percent oil dispersion) / tetrahydrofuran / 18 h / Heating View Scheme

sodium hydride in tetrahydrofuran 18 h; Heating;