tetraphosphorus decasulfide; sodium hydrogencarbonate in tetrahydrofuran T=20°C; 4 h;

1.1: tBuOK / dimethylformamide / 0.17 h / 90 °C 1.2: dimethylformamide / 2 h / 90 °C 2.1: LiCl / dimethylsulfoxide / 3 h / 100 °C 2.2: acetic acid; iron / 1 h / 100 °C 3.1: 74 percent / P2S5; NaHCO3 / tetrahydrofuran / 4 h / 20 °C View Scheme

1.1: LiCl / dimethylsulfoxide / 3 h / 100 °C 1.2: acetic acid; iron / 1 h / 100 °C 2.1: 74 percent / P2S5; NaHCO3 / tetrahydrofuran / 4 h / 20 °C View Scheme