反应详情

温度

-69 °C

To a solution of ethyl 2-(2-(tert-butoxycarbonylamino)pyridin-4-yl)acetate (10) (WO 2007089512) (10.0 g, 35.7 mmol) under nitrogen in THF (100 mL), at −78° C., was added DIBAL (1M solution in THF, 71.3 mL, 71.3 mmol) over 1 hr. The reaction mixture was stirred at −78 to −60° C. for 40 min and then warmed to −15° C. over 1 hr. The solution was re-cooled to −78° C. and treated with further DIBAL (1M solution in THF, 35 mL, 35.7 mmol). The mixture was allowed to warm to −40° C. and stirred for 1 hr. Water (10 mL) was added cautiously to quench the reaction followed by MgSO4 (20 g) and the solids removed by filtration. The filtrate was concentrated to dryness under reduced pressure and the residue subjected to column chromatography (330 g), eluting with 65% EtOAc in hexanes to give tert-butyl 4-(2-hydroxyethyl)pyridin-2-ylcarbamate (11) (6.00 g, 64%) as a yellow solid: m/z 239 (M+H)+ (ES+).

1. temperaturewarmed to −15° C. over 1 hr
2. temperatureThe solution was re-cooled to −78° C.
3. temperatureto warm to −40° C.
4. stirringstirred for 1 hr
5. customto quench the reaction
6. customthe solids removed by filtration
7. concentrationThe filtrate was concentrated to dryness under reduced pressure
8. washeluting with 65% EtOAc in hexanes