1: 1.) POCl3; 2.) 2 N NaOH / 1.) benzene, 16 h, RT; 2.) water 2: 68 percent / H2S / dimethylformamide / 1.5 h / -5 °C 3: anhydrous K2CO3 / acetone / 20 h / 20 °C 4: 61 percent / NEt3 / benzene / 5 h / Heating 5: 87 percent / Bu3SnH; α,α'-azoisobutyronitrile / benzene / 2 h / Heating View Scheme

1: anhydrous K2CO3 / acetone / 20 h / 20 °C 2: 61 percent / NEt3 / benzene / 5 h / Heating 3: 87 percent / Bu3SnH; α,α'-azoisobutyronitrile / benzene / 2 h / Heating View Scheme

1: 61 percent / NEt3 / benzene / 5 h / Heating 2: 87 percent / Bu3SnH; α,α'-azoisobutyronitrile / benzene / 2 h / Heating View Scheme

1: 68 percent / H2S / dimethylformamide / 1.5 h / -5 °C 2: anhydrous K2CO3 / acetone / 20 h / 20 °C 3: 61 percent / NEt3 / benzene / 5 h / Heating 4: 87 percent / Bu3SnH; α,α'-azoisobutyronitrile / benzene / 2 h / Heating View Scheme

hydrogen; palladium on activated charcoal in methanol