1: tert-butyl (3S)-1-(trifluoroacetyl)piperidinylcarbamate With sodium hydride in tetrahydrofuran T=0°C; 0.333333 h; 2: methyl iodide in tetrahydrofuran T=0 - 20°C; 4 h; 3: With potassium carbonate in methanol T=20°C; 16 h;