1: N-benzyloxy-4-(2,4,5-trifluorophenyl)-3(S)-hydroxybutanamide; triphenylphosphine With di-isopropyl azodicarboxylate in tetrahydrofuran T=-5 - 30°C; 3.25 h; 2: With sodium hydroxide in tetrahydrofuran; water T=65 - 70°C; 3: tert-butylamine in tert-butyl methyl ether T=25 - 30°C;

Multi-step reaction with 3 steps 1.1: hydrogenchloride / 8 h / -10 - 35 °C1.2: 0.17 h / 60 °C / Active charcoal addition2.1: sodium hydroxide; water / tetrahydrofuran / 2.17 h / 40 °C3.1: diisopropyl-carbodiimide; N-ethyl-N,N-diisopropylamine / dichloromethane / 16 h / 2 - 23 °C