1: 73 percent / Na2S / dimethylformamide / 3 h / 100 °C 2: 82 percent / diethyl azodicarboxylate, PPh3 / tetrahydrofuran / 0.83 h / Ambient temperature 3: 81 percent / K2CO3 / methanol / 0.5 h 4: 94 percent / DMAP / CH2Cl2 / 1 h / 0 °C 5: 26 percent / K2CO3 / dimethylsulfoxide / 85 °C 6: 1) BBr3, 2) aq. NH3 / 1) CH2Cl2, 2) CH2Cl2, 45 min View Scheme

1: 73 percent / Na2S / dimethylformamide / 3 h / 100 °C 2: 82 percent / diethyl azodicarboxylate, PPh3 / tetrahydrofuran / 0.83 h / Ambient temperature 3: 81 percent / K2CO3 / methanol / 0.5 h 4: 94 percent / DMAP / CH2Cl2 / 1 h / 0 °C 5: 11 percent / K2CO3 / dimethylsulfoxide / 85 °C 6: 1) BBr3, 2) aq. NH3 / 1) CH2Cl2, 2) CH2Cl2, 45 min View Scheme

1: 73 percent / Na2S / dimethylformamide / 3 h / 100 °C 2: 82 percent / diethyl azodicarboxylate, PPh3 / tetrahydrofuran / 0.83 h / Ambient temperature 3: 81 percent / K2CO3 / methanol / 0.5 h 4: 94 percent / DMAP / CH2Cl2 / 1 h / 0 °C 5: 26 percent / K2CO3 / dimethylsulfoxide / 85 °C 6: 1) BBr3, 2) aq. NH3 / 1) CH2Cl2, 2) CH2Cl2, 45 min View Scheme