toluene-4-sulfonic acid in diethyl ether; acetic acid 72 h; Ambient temperature;

1: 87.2 percent / K2CO3 / acetonitrile / 3 h / Ambient temperature 2: 96 percent / p-toluenesulfonic acid / dimethylformamide / 0.17 h / 125 - 130 °C View Scheme

potassium carbonate in acetonitrile 3 h; Ambient temperature;