1: 92 percent / aq. sodium hydroxide / ethanol / 1 h / Heating 2: 1.19 g / tetrahydrothiophene 1,1-dioxide / heating, then distilling View Scheme

sodium hydroxide in ethanol 1 h; Heating;

<b>Multi-step reaction with 3 steps<br /> </b>1: hydrogen chloride<br />2: 1.89 g / potassium hydroxide<br />3: aq. hydrochloric acid, acetic acid / 1.5 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: 1.89 g / potassium hydroxide<br />2: aq. hydrochloric acid, acetic acid / 1.5 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: 1.76 g / 2 h / 70 &deg;C / or toluene-p-sulphonic acid, room temp., 33h<br />2: 1.89 g / potassium hydroxide<br />3: aq. hydrochloric acid, acetic acid / 1.5 h<br /> <br /> &nbsp;