1: With sulfuric acid; sodium nitrite in water T=0°C; 1 h; Cooling with ice; 2: With potassium iodide in water T=0 - 80°C; 1 h;

1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With N,N-dimethyl-formamide in tetrahydrofuran; hexane T=-78 - 20°C; 2 h;