反应详情

Triethylsilane (80 mL, 493 mmol) was added dropwise to a solution of ethyl (4-nitro-1H-indol-3-yl)(oxo)acetate from Step A (6.46 g, 24.6 mmol) in TFA (100 mL). After 3 h, the reaction mixture was concentrated in vacuo and the residue was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:MeOH—100:0 to 99:1, to give the racemic product. The enantiomers were resolved by HPLC, utilizing a Chiralcel OD column and eluting with hexane:i-PrOH—70:30. The first major peak to elute was ethyl (4-nitro-2,3-dihydro-1H-indol-3-yl)acetate, enantiomer A, and the second major peak to elute was ethyl (4-nitro-2,3-dihydro-1H-indol-3-yl)acetate, enantiomer B, the title compound. MS: m/z=251 (M+1).

1. concentrationthe reaction mixture was concentrated in vacuo
2. customthe residue was purified by silica gel chromatography
3. washeluting with a gradient of CH2Cl2
4. customMeOH—100:0 to 99:1, to give the racemic product
5. washeluting with hexane
6. washThe first major peak to elute
7. washthe second major peak to elute