1: 99.4 percent / CH2Cl2 / 6.3 h / Ambient temperature 2: 56 percent / thionyl chloride / CH2Cl2; dimethylformamide / 4 h / 25 °C 3: 95.5 percent / hydrogen, triethylamine / 5percent Pd/C / ethyl acetate / 4.5 h / Ambient temperature 4: 283 mg / liq. ammonia / 96 h / Ambient temperature View Scheme