1: 78 percent / triethylamine / tetrahydrofuran / 16 h / Ambient temperature 2: 910 mg / hydrogen / PtO2 / methanol / 1 h / Ambient temperature 3: 28 percent / 1,3-diisopropylcarbodiimide / acetonitrile / 16 h / Ambient temperature View Scheme

diisopropyl-carbodiimide in acetonitrile 16 h; Ambient temperature;

1: 70 percent / dimethylformamide / 2 h / 120 °C 2: 88 percent / hydrochloric acid / 1 h / 60 °C 3: 28 percent / 1,3-diisopropylcarbodiimide / acetonitrile / 16 h / Ambient temperature View Scheme

1: 71 percent / 1,8-diazabicyclo<5.4.0>undec-7-ene, N,N-diisopropylethylamine / butan-1-ol / 3 h / Heating 2: 70 percent / dimethylformamide / 2 h / 120 °C 3: 88 percent / hydrochloric acid / 1 h / 60 °C 4: 28 percent / 1,3-diisopropylcarbodiimide / acetonitrile / 16 h / Ambient temperature View Scheme