ammonium acetate T=120 - 130°C; 2 h;

trifluoroacetic acid T=25°C; 0.5 h; Inert atmosphere;

1: 1.) 2,3-dichloro-5,6-dicyan-p-benzoquinone; 2.) potassium carbonate / 1.) tetrahydrofuran, water, room temperature, 10 h; 2.) 1 h 2: 1.) potassium hydroxide / 1.) DMSO, 0.5 h; 2.) room temperature, 2 h 3: 91 percent / ammonium acetate / 2 h / 120 - 130 °C View Scheme

1: 1.) potassium hydroxide / 1.) DMSO, 0.5 h; 2.) room temperature, 2 h 2: 91 percent / ammonium acetate / 2 h / 120 - 130 °C View Scheme

1: POCl3 2: AcOH View Scheme

lithium aluminium tetrahydride in tetrahydrofuran

sodium tetrahydroborate in tetrahydrofuran; methanol 1 h; Ambient temperature;