1: 50 percent / acide toluene-p-sulfonique / methanol / 2 h / Heating 2: 90 percent / chlorure de p-toluene sulfonyle, NaOH / benzene; H2O / 22 h View Scheme

1: 50 percent / acide toluene-p-sulfonique / methanol / 2 h / Heating 2: 95 percent / acide sulfurique, chlorure de toluene-p-sulfonyle / benzene; H2O / 16 h View Scheme