1: With hydrogenchloride in ethanol; water T=50°C; 1.5 h; 2: With potassium hydroxide in ethanol; water T=5 - 78°C; pH=5 - 11; Cooling;

1.1: potassium tert-butylate / ethylene glycol dimethyl ether / 0.67 h / -60 - -55 °C 1.2: -55 - 85 °C 2.1: potassium tert-butylate / ethylene glycol dimethyl ether / 18 h / 85 °C / |Sealed tube 3.1: hydrazine monohydrochloride / ethanol / 15 h / 90 °C 3.2: |Cooling 4.1: ethanol / 18 h / 45 °C 5.1: N-bromosuccinmide / dichloromethane; acetonitrile 6.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 6.2: 4 h / 20 °C View Scheme

1.1: potassium tert-butylate / ethylene glycol dimethyl ether / 18 h / 85 °C / |Sealed tube 2.1: hydrazine monohydrochloride / ethanol / 15 h / 90 °C 2.2: |Cooling 3.1: ethanol / 18 h / 45 °C 4.1: N-bromosuccinmide / dichloromethane; acetonitrile 5.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 5.2: 4 h / 20 °C View Scheme

1.1: hydrazine monohydrochloride / ethanol / 15 h / 90 °C 1.2: |Cooling 2.1: ethanol / 18 h / 45 °C 3.1: N-bromosuccinmide / dichloromethane; acetonitrile 4.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 4.2: 4 h / 20 °C View Scheme

1.1: ethanol / 18 h / 45 °C 2.1: N-bromosuccinmide / dichloromethane; acetonitrile 3.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 3.2: 4 h / 20 °C View Scheme

1.1: tetrahydrofuran / 18 h / 25 °C 2.1: lithium hexamethyldisilazane / tetrahydrofuran / 1 h / -78 °C 2.2: 0.67 h / -78 °C 3.1: ethanol / 18 h / 45 °C 4.1: N-bromosuccinmide / dichloromethane; acetonitrile 5.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 5.2: 4 h / 20 °C View Scheme

1.1: ethanol / 18 h / 45 °C 2.1: N-bromosuccinmide / dichloromethane; acetonitrile 3.1: trifluoroacetic acid / dichloromethane / 0.5 h / 0 °C 3.2: 4 h / 20 °C View Scheme