1: in methanol; water T=20 - 66°C; 1.5 h; 2: With sodium hydroxide in methanol; water T=40 - 45°C; 3: With hydrogenchloride in methanol; water T=20 - 25°C; Product distribution / selectivity;

in acetic acid Reflux;

1: 4-hydrazino-benzoic acid hydrochloride; 4-piperidone-monohydrite, hydrochloride With hydrogenchloride in 1,4-dioxane; water Heating / reflux; 2: di-tert-butyl dicarbonate With sodium hydroxide in methanol T=20°C; pH=~ 9 - 10; 3: With acetic acid in water pH=~ 5;

1: hydrogenchloride / 1,4-dioxane / 3 h / |Reflux 2: sodium hydroxide / water; methanol / 20 °C / pH 9 - 10 View Scheme

in acetic acid 12 h; Reflux;

hydrogenchloride in 1,4-dioxane T=17°C; Heating / reflux;

in hydrogenchloride; acetic acid