1: With boron tribromide in dichloromethane T=-78 - 0°C; Inert atmosphere; 2: With water in dichloromethane T=0°C;

sodium hydride; ethanethiol in N,N-dimethyl-formamide 3 h; Heating;

1: diethyl ether / 2.5 h / Heating 2: 29 percent / PBr3 / CHCl3 / Ambient temperature; 1.) ice-water bath cooling, 30 min, 2.) r.t., overnight 3: 30 percent / NaH, ethanethiol / dimethylformamide / 3 h / Heating View Scheme