反应详情

Diisobutylaluminium hydride (1 M in DCM, 41.6 mL, 41.6 mmol, 1.3 equiv) was added dropwise to a cold (−78° C.) solution of 5-nitro-pyridine-2-carboxylic acid ethyl ester (Step 39.4) (6.4 g, 32 mmol) in DCM (120 mL), under an argon atmosphere. The reaction mixture was allowed to warm to rt, quenched by addition of an aqueous solution of potassium sodium tartrate, diluted with DCM and H2O, and filtered through a pad of celite. The filtrate was extracted several times with DCM. The organic phase was washed with brine, dried (Na2SO4), filtered and concentrated. The residue was purified by silica gel column chromatography (Hex/EtOAc, 9:1→1:1) to provide 1.44 g of the title compound: ESI-MS: 153.1 [M−H]−.

1. customquenched by addition of an aqueous solution of potassium sodium tartrate
2. additiondiluted with DCM and H2O
3. filtrationfiltered through a pad of celite
4. extractionThe filtrate was extracted several times with DCM
5. washThe organic phase was washed with brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by silica gel column chromatography (Hex/EtOAc, 9:1→1:1)