1: thiophosgene With triethylamine in ethyl acetate T=-78°C; 0.5 h; 2: tert-butyl 2-aminobenzoate in ethyl acetate T=-78 - 20°C; 20.5 h;

1.1: oxalyl dichloride; N,N-dimethyl-formamide / dichloromethane / 2 h 2.1: zinc(II) chloride / pyridine / 12 h 3.1: palladium on activated charcoal; hydrogen / ethanol / 72 h / 1520.1 Torr 4.1: triethylamine / ethyl acetate / 0.5 h / -78 °C 4.2: 20.5 h / -78 - 20 °C View Scheme

1.1: palladium on activated charcoal; hydrogen / ethanol / 72 h / 1520.1 Torr 2.1: triethylamine / ethyl acetate / 0.5 h / -78 °C 2.2: 20.5 h / -78 - 20 °C View Scheme

1.1: zinc(II) chloride / pyridine / 12 h 2.1: palladium on activated charcoal; hydrogen / ethanol / 72 h / 1520.1 Torr 3.1: triethylamine / ethyl acetate / 0.5 h / -78 °C 3.2: 20.5 h / -78 - 20 °C View Scheme