toluene-4-sulfonic acid 24 h; Heating;

1: 63 percent / Br2, I2 / acetic acid / 72 h / Ambient temperature 2: 91 percent / TsOH / ethanol / 2 h / Heating View Scheme

1: 1.) 15 percent BuLi / 1.) ether, hexane, 0 deg C, 3 h, 2.) -50 deg C, 30 min; room temp., 1 h 2: 92 percent / 85 percent H3PO4 / dioxane; H2O / 12 h / Ambient temperature 3: 20 percent / Triton B / methanol / 16 h / Heating View Scheme