1.1: hydrogenchloride / isopropyl alcohol / 16 h / 5 - 25 °C 2.1: sodium hydroxide / water; 2-methyl tetrahydrofuran / pH > 12 2.2: 16 h / 65 °C 3.1: hydrogenchloride / water / 1 h / 65 °C / pH 1 3.2: 15 - 25 °C / pH >= 12 View Scheme