hydrogenchloride in methanol; isopropyl alcohol T=4 - 20°C; 12 h;

1: 1-fluoro-4-acetyl-benzene With dimethylsulfide borane complex; chiral oxazaborolidine in dichloromethane Corey-Bakshi-Shibata reduction; 2: With hydrogen bromide in n-heptane 3: piperazine Further stages.;

1: phosphorus tribromide / dichloromethane / 4 h / 4 - 20 °C 2: potassium carbonate / N,N-dimethyl-formamide / 2 h / 20 °C 3: hydrogenchloride / isopropyl alcohol; methanol / 12 h / 4 - 20 °C View Scheme

1: AlCl3, aluminium chloride / 2 h / 4 °C 2: sodium tetrahydroborate; methanol / 1.25 h / 4 °C 3: phosphorus tribromide / dichloromethane / 4 h / 4 - 20 °C 4: potassium carbonate / N,N-dimethyl-formamide / 2 h / 20 °C 5: hydrogenchloride / isopropyl alcohol; methanol / 12 h / 4 - 20 °C View Scheme

1: sodium tetrahydroborate; methanol / 1.25 h / 4 °C 2: phosphorus tribromide / dichloromethane / 4 h / 4 - 20 °C 3: potassium carbonate / N,N-dimethyl-formamide / 2 h / 20 °C 4: hydrogenchloride / isopropyl alcohol; methanol / 12 h / 4 - 20 °C View Scheme

1: potassium carbonate / N,N-dimethyl-formamide / 2 h / 20 °C 2: hydrogenchloride / isopropyl alcohol; methanol / 12 h / 4 - 20 °C View Scheme