in ethyl acetate T=25°C; 12 h;

sulfuric acid in ethanol T=20°C; 1 h;

sulfuric acid in ethanol 1 h; Reflux;

sulfuric acid in ethanol T=20°C; 1 h; Inert atmosphere;

1.1: potassium carbonate / acetone / 22 h / 60 °C / Inert atmosphere 2.1: water; sodium hydroxide / tetrahydrofuran; methanol; dichloromethane / 20 °C 3.1: thionyl chloride / chloroform / Inert atmosphere 4.1: triethylamine / dichloromethane 5.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 5.2: -78 °C 6.1: 1 h / Reflux 7.1: hydrazine hydrate / methanol / 1 h / Reflux 8.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme

1.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 1.2: -78 °C 2.1: 1 h / Reflux 3.1: hydrazine hydrate / methanol / 1 h / Reflux 4.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme

1: 1 h / Reflux 2: hydrazine hydrate / methanol / 1 h / Reflux 3: sulfuric acid / ethanol / 1 h / Reflux View Scheme

1.1: thionyl chloride / chloroform / Inert atmosphere 2.1: triethylamine / dichloromethane 3.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 3.2: -78 °C 4.1: 1 h / Reflux 5.1: hydrazine hydrate / methanol / 1 h / Reflux 6.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme

1.1: water; sodium hydroxide / tetrahydrofuran; methanol; dichloromethane / 20 °C 2.1: thionyl chloride / chloroform / Inert atmosphere 3.1: triethylamine / dichloromethane 4.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 4.2: -78 °C 5.1: 1 h / Reflux 6.1: hydrazine hydrate / methanol / 1 h / Reflux 7.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme

1.1: triethylamine / dichloromethane 2.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 2.2: -78 °C 3.1: 1 h / Reflux 4.1: hydrazine hydrate / methanol / 1 h / Reflux 5.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme