1: 3-ethyl 1-(phenylmethyl) 1,3-piperidinedicarboxylate With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 0.333333 h; 2: methyl iodide in tetrahydrofuran T=-78 - 20°C;

1: With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 0.583333 h; 2: With methyl iodide in tetrahydrofuran T=-78 - 20°C;

1.1: sodium carbonate / water; tetrahydrofuran / 0.33 h / 20 °C 1.2: 2 h / 20 °C 2.1: N,N'-dimethyl-N,N'-propyleneurea; lithium hexamethyldisilazane / tetrahydrofuran / 1 h / -78 - -60 °C 2.2: 2.5 h / -60 - -20 °C View Scheme

1: With water; lithium hydroxide hydrate in ethanol T=86°C; 1 h; 2: With potassium hydrogensulfate in water pH=3 - 4;

hydrogen; palladium 10 on activated carbon in methanol T=20°C; 2.5 h;