1: 58 g / p-toluenesulfonic acid / benzene / 6 h / Heating View Scheme

toluene-4-sulfonic acid in methanol

in P2O5

toluene-4-sulfonic acid

in diethyl ether

bromine in tetrachloromethane 2 h; Ambient temperature;

1: p-toluenesulfonic acid / benzene / 7 h / Heating 2: 28.6 g / p-toluenesulfonic acid / benzene / Heating 3: Br2, CaCO3 / CHCl3; CCl4 / 0.5 h / 5 °C View Scheme

1: p-toluenesulfonic acid / benzene / 7 h / Heating 2: 28.6 g / p-toluenesulfonic acid / benzene / Heating 3: Br2, CaCO3 / CHCl3; CCl4 / 0.5 h / 5 °C 4: 72 percent / LiBr2, Li2CO3 / dimethylformamide / 0.5 h / Heating 5: 100 percent / N-bromosuccinimide, 2,2-azadiisobutyronitrile / CCl4 / 5 h / Heating 6: 62 percent / H2O / dioxane / 2.5 h / Heating View Scheme

1: p-toluenesulfonic acid / benzene / 7 h / Heating 2: 28.6 g / p-toluenesulfonic acid / benzene / Heating 3: Br2, CaCO3 / CHCl3; CCl4 / 0.5 h / 5 °C 4: 72 percent / LiBr2, Li2CO3 / dimethylformamide / 0.5 h / Heating 5: 100 percent / N-bromosuccinimide, 2,2-azadiisobutyronitrile / CCl4 / 5 h / Heating 6: 62 percent / H2O / dioxane / 2.5 h / Heating 7: 72 percent / conc. HCl / 4 h / Ambient temperature View Scheme

1: 8.7 g / Br2 / CCl4 / 2 h / Ambient temperature 2: 6.1 g / NaOH / H2O / 6 h / Heating View Scheme