1: trifluoroacetic acid / 0.67 h 2: diisopropylethylamine, 1-hydroxybenzotriazole / dimethylformamide / 12 h / Ambient temperature 3: trifluoroacetic acid / 0.67 h 4: diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature 5: 80 percent / hydrogen / 10percent Pd/BaSO4 / dimethylformamide; H2O; various solvent(s) / 24 h View Scheme

1: trifluoroacetic acid / 0.67 h 2: diisopropylethylamine, 1-hydroxybenzotriazole / dimethylformamide / 12 h / Ambient temperature 3: trifluoroacetic acid / 0.67 h 4: diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature View Scheme