tetrabutyl-ammonium chloride in tetrahydrofuran; water T=65°C; 0.0833333 h;

1: 4-methoxybenzenesulfonic acid pyridinium salt With trifluoromethanesulfonic acid anhydride; triphenyl-phosphine oxide in dichloromethane 2: 2,3,4,5,6-pentafluorophenol With triethylamine in dichloromethane T=0 - 20°C;