1: hydrogenchloride; benzotriazol-1-ol / 1-methyl-pyrrolidin-2-one / 4 h / 120 °C / Inert atmosphere 2: 3-chloro-benzenecarboperoxoic acid / dichloromethane / 5 - 20 °C 3: ammonium hydroxide; p-toluenesulfonyl chloride / dichloromethane / 0 - 20 °C 4: hydrogenchloride / water; methanol / 1 h / 50 °C View Scheme