toluene-4-sulfonic acid in benzene 48 h; Heating;

1: 1.) PhLi / 1.) ether, -20 deg C, 15 min, 2.) ether, from -20 deg C to RT 2: 82 percent / propionic acid / 2 h / 138 °C 3: 65 percent / p-toluenesulfonic acid, water / acetone / 24 h / Heating 4: 84 percent / NaCN, MnO2, NH3 / propan-2-ol / 4 h / 0 °C 5: 96 percent / aq. KOH / ethanol / 2 h / Ambient temperature View Scheme