1: With n-butyllithium in tetrahydrofuran 0.5 h; 2: With selenium in tetrahydrofuran 0.5 h; 3: With copper(ll) bromide in tetrahydrofuran T=-78 - 20°C;

in diethyl ether 3 h;

1: 81 percent / thionyl chloride / 3 h / Heating 2: 65 percent / diethyl ether / 3 h View Scheme

1: 1.)HCl, sodium nitrite 2.) sodium diselenide, HCl / 1.)H2O, 5 degC 2.) 2 h 2: 81 percent / thionyl chloride / 3 h / Heating 3: 65 percent / diethyl ether / 3 h View Scheme