[CH2:1]([O:3][C:4]([C:6]1([C:17]#[N:18])[CH2:9][N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:7]1)=[O:5])C.[H][H]>CO.[Ni]>[CH3:1][O:3][C:4]([C:6]1([CH2:17][NH2:18])[CH2:9][N:8]([C:10]([O:12][C:13]([CH3:14])([CH3:16])[CH3:15])=[O:11])[CH2:7]1)=[O:5]3-Cyano-azetidine-1,3-dicarboxylic acid 1-tert-butyl ester 3-ethyl ester (7.75 g; 30.5 mmol) in methanol (1000 ml) is combined with wet RaNi (˜28 g) and hydrogenated at room temperature under 1 atm of hydrogen for 2 hours. The reaction mixture is filtered and evaporated to dryness to yield the title compound as light brown resin, which crystallizes slowly (6.8 g; 91%).
Wird geladen…