反应详情

To an ice-cooled solution of 1,1-(azodicarbonyl) dipiperidine (18.08 g, 71.7 mmol) in anhydrous THF (200 mL) is added via syringe tributylphosphine (17.69 mL, 79.7 mmol) and allowed to stir for 2.5 hours. To this ice-cooled mixture is added a solution of (3-hydroxy-phenyl)-carbamic acid tert-butyl ester (10.0 g, 47.8 mmol) and 4-hydroxy-piperidine-1-carboxylic acid benzyl ester (7.23 mL, 47.8 mmol) in anhydrous THF (30 mL) causing a light yellow precipitate to form. The mixture is warmed to room temperature and stirred overnight. The mixture is filtered through a fritted funnel and washed solid with THF (3×15 mL). After removal of solvent, the residue is purified on a silica gel chromatography with ethyl acetate-hexanes to provide a clear oil (11.8 g, 57.9% yield, ES+(m/z) 427.2 [M+H]).

1. customto form
2. stirringstirred overnight
3. filtrationThe mixture is filtered through a fritted funnel
4. washwashed solid with THF (3×15 mL)
5. customAfter removal of solvent
6. customthe residue is purified on a silica gel chromatography with ethyl acetate-hexanes
7. customto provide a clear oil (11.8 g, 57.9% yield, ES+(m/z) 427.2 [M+H])