boron dimethyl-trifluoro sulphide in dichloromethane T=20°C; 6 h; in the dark;

1: 90 percent / PCl5 / diethyl ether / 0.33 h 2: 82 percent / TiCl4 / CH2Cl2 / 5.5 h / 20 °C / in the dark 3: 53 percent / BF3*SMe2 / CH2Cl2 / 6 h / 20 °C / in the dark View Scheme

1: 82 percent / TiCl4 / CH2Cl2 / 5.5 h / 20 °C / in the dark 2: 53 percent / BF3*SMe2 / CH2Cl2 / 6 h / 20 °C / in the dark View Scheme

1: 1.) NaNO2; 2.) NaN3 / 1.) TFA, 0 deg C, 0.5 h; 2.) Et2O, 1 h 2: 90 percent / PCl5 / diethyl ether / 0.33 h 3: 82 percent / TiCl4 / CH2Cl2 / 5.5 h / 20 °C / in the dark 4: 53 percent / BF3*SMe2 / CH2Cl2 / 6 h / 20 °C / in the dark View Scheme

sodium azide; sodium nitrite 1.) 5percent HCl, acetone, 0 deg C, 30 min; 2.) H2O, 30 min; Yield given. Multistep reaction;