1: diisopropylethylamine, 1-hydroxybenzotriazole / dimethylformamide / 12 h / Ambient temperature 2: trifluoroacetic acid / 0.67 h 3: diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature 4: 80 percent / hydrogen / 10percent Pd/BaSO4 / dimethylformamide; H2O; various solvent(s) / 24 h View Scheme

1: diisopropylethylamine, 1-hydroxybenzotriazole / dimethylformamide / 12 h / Ambient temperature 2: trifluoroacetic acid / 0.67 h 3: diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature View Scheme