反应详情

Place 4-(3-chloro-5-nitro-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (3.09 g, 9.01 mmol) in methanol (50 mL). Add nickel(II) chloride hexahydrate (10.7 g, 45.1 mmol) and cool the reaction to 0° C. Add sodium borohydride (5.11 g, 135.15 mmol) in portions and stir at 0° C. for 2 hours. Add CH2Cl2 and filter through a pad of Celite®. Wash filter cake with CH2Cl2 and collect filtrate. Add saturated aq. sodium bicarbonate solution to the filtrate and separate organic layer. Extract aqueous layer with CH2Cl2 (2×30 mL). Combine organic extracts, dry over Mg2SO4, filter, and concentrate under reduced pressure. Subject residue to silica gel chromatography eluting with 0-70% EtOAc:hexane to yield 1.77 g (63%) of the title compound. MS(ES): m/z=311.2 [M−H].

1. customthe reaction to 0° C
2. filtrationAdd CH2Cl2 and filter through a pad of Celite®
3. washWash
4. filtrationfilter cake with CH2Cl2
5. customcollect filtrate
6. customAdd saturated aq. sodium bicarbonate solution to the filtrate and separate organic layer
7. dry with materialCombine organic extracts, dry over Mg2SO4
8. filtrationfilter
9. concentrationconcentrate under reduced pressure
10. washSubject residue to silica gel chromatography eluting with 0-70% EtOAc