acetic acid T=95°C; 0.916667 h;

2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in toluene 2.5 h; Heating;

1: 1.) Bu3SnH, azobis(isobutyronitrile) (AIBN) / 1.) benzene, reflux, 1 h, 2.) DMF, 2.5 h 2: 73 percent Spectr. / Bu3SnH, azobis(isobutyronitrile) (AIBN) / toluene / 2.5 h / Heating View Scheme

1: 94 percent / triethylamine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 18 h 2: silver oxide / 3 h / Heating 3: 72 percent / 2 M NaOH / pyridine; ethanol / 1.5 h / 0 °C 4: 84 percent / 80 percent acetic acid / 0.92 h / 95 °C View Scheme

Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;