hydrogenchloride in ethanol; ethyl acetate T=15 - 20°C; 1 h; Industry scale;

1: With borane-THF in tetrahydrofuran T=20 - 50°C; 2: With methanol in tetrahydrofuran T=0 - 5°C; 0.25 h; 3: With hydrogenchloride in ethyl acetate T=0°C; 2.5 h; Reflux;

1.1: potassium hydroxide; water / 4 h / Reflux 1.2: 20 °C 2.1: ethyl acetate / 1.25 h / 0 °C / Reflux 3.1: hydrogenchloride / dichloromethane; water / 0.08 h 4.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 5.1: dichloromethane; water / 0 - 10 °C 6.1: borane-THF / tetrahydrofuran / 20 - 50 °C 6.2: 0.25 h / 0 - 5 °C 6.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: ethyl acetate / 1.25 h / 0 °C / Reflux 2.1: hydrogenchloride / dichloromethane; water / 0.08 h 3.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 4.1: dichloromethane; water / 0 - 10 °C 5.1: borane-THF / tetrahydrofuran / 20 - 50 °C 5.2: 0.25 h / 0 - 5 °C 5.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: potassium hydroxide / water / 4 h 1.2: 0.5 h / Cooling with ice-water bath 2.1: ethyl acetate / 1.25 h / 0 °C / Reflux 3.1: hydrogenchloride / dichloromethane; water / 0.08 h 4.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 5.1: dichloromethane; water / 0 - 10 °C 6.1: borane-THF / tetrahydrofuran / 20 - 50 °C 6.2: 0.25 h / 0 - 5 °C 6.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: n-butyllithium / hexane; tetrahydrofuran / -10 °C / Inert atmosphere 2.1: potassium hydroxide; water / 4 h / Reflux 2.2: 20 °C 3.1: ethyl acetate / 1.25 h / 0 °C / Reflux 4.1: hydrogenchloride / dichloromethane; water / 0.08 h 5.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 6.1: dichloromethane; water / 0 - 10 °C 7.1: borane-THF / tetrahydrofuran / 20 - 50 °C 7.2: 0.25 h / 0 - 5 °C 7.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 2.1: dichloromethane; water / 0 - 10 °C 3.1: borane-THF / tetrahydrofuran / 20 - 50 °C 3.2: 0.25 h / 0 - 5 °C 3.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: hydrogenchloride / dichloromethane; water / 0.33 h 2.1: oxalyl dichloride / N,N-dimethyl-formamide / dichloromethane / 15 - 25 °C 3.1: dichloromethane; water / 0 - 10 °C 4.1: borane-THF / tetrahydrofuran / 20 - 50 °C 4.2: 0.25 h / 0 - 5 °C 4.3: 2.5 h / 0 °C / Reflux View Scheme

1.1: dichloromethane; water / 0 - 10 °C 2.1: borane-THF / tetrahydrofuran / 20 - 50 °C 2.2: 0.25 h / 0 - 5 °C 2.3: 2.5 h / 0 °C / Reflux View Scheme

1: triethylamine / tetrahydrofuran; N,N-dimethyl-formamide / 24 h / 50 °C 2: thionyl chloride; triethylamine / dichloromethane / 3 h / 20 - 40 °C 3: potassium iodide; triethylamine / acetonitrile / 24 h / 20 - 60 °C 4: sodium hydroxide / ethanol; water / 6 h / |Reflux 5: thionyl chloride; triethylamine / dichloromethane / 1 h / 5 - 30 °C View Scheme