1: 44 percent / diphenyl ether; biphenyl / 0.03 h / Heating 2: 45 percent / POCl3, N,N-diethylaniline / 12 h / Heating 3: 89 percent / Na / 2 h / Ambient temperature 4: 56 percent / H2, NaOAc / 5percent Pd/C / dimethylformamide / 1 h / 2280 Torr 5: 73 percent / LiBH4 / tetrahydrofuran 6: 69 percent / NH3 / methanol / 116 h / 140 - 175 °C / 45600 Torr View Scheme