1: With triethylamine; zinc(II) chloride in dichloromethane T=2 - 20°C; Industry scale; 2: With hydrogenchloride in dichloromethane; water; ethyl acetate 0.0833333 h; Industry scale;

1.1: sulfuric acid / water / 20.5 h / 20 - 60 °C / Industry scale 2.1: 1,1'-carbonyldiimidazole / tetrahydrofuran / 0.17 h 2.2: 2 h 3.1: diisobutylaluminium hydride / toluene / 5 - 20 °C 4.1: potassium tert-butylate / toluene / 0.5 h / 80 °C 4.2: 1 h / 20 °C 5.1: toluene-4-sulfonic acid / 20 °C 6.1: sodium hydride; ethanethiol / N,N'-dimethyl-N,N'-propyleneurea / 2 h / 130 °C 6.2: Cooling with ice-water 7.1: toluene-4-sulfonic acid / toluene / 24 h View Scheme