triethylamine in ethylene glycol dimethyl ether 18 h; Ambient temperature;

triethylamine in 1,4-dioxane; dichloromethane T=0 - 20°C; 16 h;

1: 75 percent / diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature 2: trifluoroacetic acid / 0.67 h 3: diisopropylethylamine, 1-hydroxybenzotriazole / dimethylformamide / 12 h / Ambient temperature 4: trifluoroacetic acid / 0.67 h 5: diisopropylethylamine / dimethylformamide / 12 h / Ambient temperature View Scheme

sodium hydrogencarbonate in 1,4-dioxane T=20°C;