potassium carbonate in acetonitrile 3 h; Ambient temperature;

1: 19.4 percent / p-toluenesulfonic acid / acetic acid; diethyl ether / 72 h / Ambient temperature 2: 87.2 percent / K2CO3 / acetonitrile / 3 h / Ambient temperature View Scheme

toluene-4-sulfonic acid in N,N-dimethyl-formamide T=125 - 130°C; 0.166667 h;