Triethylsilane → Ethyl (4-nitro-2,3-dihydro-1H-indol-3-yl)acetate

HRID 551008Notes

Reaction equation

HRID 551008 reaction equation
C([SiH](CC)CC)C.[N+:8]([C:11]1[CH:19]=[CH:18][CH:17]=[C:16]2[C:12]=1[C:13]([C:20](=O)[C:21]([O:23][CH2:24][CH3:25])=[O:22])=[CH:14][NH:15]2)([O-:10])=[O:9]>C(O)(C(F)(F)F)=O>[N+:8]([C:11]1[CH:19]=[CH:18][CH:17]=[C:16]2[C:12]=1[CH:13]([CH2:20][C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH2:14][NH:15]2)([O-:10])=[O:9]

Participants

4

Reactant 2

HCID 12052TriethylsilaneHCID 14131875ethyl 2-(4-nitro-1H-indol-3-yl)-2-oxoacetate

Product 1

HCID 57457652Ethyl (4-nitro-2,3-dihydro-1H-indol-3-yl)acetate

Reagents, catalysts & solvents 1

HCID 6422Trifluoroacetic acidSolvent

Procedure

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).

Workup

  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

Sources & evidence

ORD record
ord-0f66973316b94ca49138167dab681590
Source dataset
uspto-grants-2011_05
Patent number
US07947677B2

Reaction notes

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