[OH:1][CH:2]1[C:7](=O)[CH2:6][CH2:5][N:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:3]1.[C:14](#[N:18])[CH2:15][C:16]#[N:17].C(NCC)C>C(O)C>[NH2:18][C:14]1[O:1][C:2]2[CH2:3][N:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:5][CH2:6][C:7]=2[C:15]=1[C:16]#[N:17]Ethyl 3-hydroxy-4-oxopiperidine-1-carboxylate from Example 35A (4.00 g, 21.4 mmol) was dissolved in ethanol (10 mL), and propanedinitrile (1.41 g, 21.4 mmol) was added. Within 10 min, diethylamine (1.56 g, 21.4 mmol) was added dropwise, whilst the temperature was kept below 35° C. Subsequently, the reaction mixture was stirred for 20 h at rt. The precipitate was collected by suction filtration and washed with ethanol and diethyl ether to yield 2.00 g (39%) of the title compound.
Wird geladen…
