ethanolamine in tetrahydrofuran T=80°C; 24 h;

1: bis-((R)-2,5-dioxo-imidazolidin-4-ylmethyl)-disulfide With potassium carbonate in N,N-dimethyl-formamide T=40°C; 2: benzyl bromide in N,N-dimethyl-formamide T=40 - 50°C; 3 h;

sodium hydride in N,N-dimethyl-formamide T=23°C; 20 h;

potassium carbonate T=40 - 50°C; 3 h;

1.1: H2O / 0.75 h / Heating 1.2: 32 percent / aq. HCl / 2 h / pH 2 / Heating 2.1: 88 percent / sodium hydride / dimethylformamide / 20 h / 23 °C View Scheme

1.1: sodium methylate / methanol / 1 h / 60 °C / Inert atmosphere 1.2: 14 h / 60 °C 2.1: sodium hydride / 1,4-dioxane / 1.5 h / 90 °C / Inert atmosphere 2.2: 14 h / 110 °C 3.1: ethanolamine / tetrahydrofuran / 24 h / 80 °C View Scheme