1: 91 percent / p-toluenesulfonic acid / toluene / 6 h / Heating 2: 100 percent / 2N aq. NaOH / 4 h / Ambient temperature View Scheme

1: 75 percent / 2N aq. NaOH / aq. ethanol / 24 h / Ambient temperature 2: 91 percent / p-toluenesulfonic acid / toluene / 6 h / Heating 3: 100 percent / 2N aq. NaOH / 4 h / Ambient temperature View Scheme

sodium hydroxide 12 h; Heating;