tert-Butyl 6-nitro-2,3-dihydro-1H-indole-1-carboxylate → tert-Butyl 6-amino-2,3-dihydro-1H-indole-1-carboxylate

HRID 1171894Notes

Reaction equation

HRID 1171894 reaction equation
[N+:1]([C:4]1[CH:12]=[C:11]2[C:7]([CH2:8][CH2:9][N:10]2[C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])=[CH:6][CH:5]=1)([O-])=O>CC(O)=O.O.[Fe]>[NH2:1][C:4]1[CH:12]=[C:11]2[C:7]([CH2:8][CH2:9][N:10]2[C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])=[CH:6][CH:5]=1

Participants

4

Reactant 1

HCID 54458177tert-Butyl 6-nitro-2,3-dihydro-1H-indole-1-carboxylate

Product 1

HCID 21936857tert-Butyl 6-amino-2,3-dihydro-1H-indole-1-carboxylate

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 21899381Acetic acid--water (1/1)Solvent

Procedure

To a solution of tert-butyl 6-nitroindoline-1-carboxylate (270 mg, 1.02 mmol) in AcOH/H2O (2.5 mL, 10:1, v:v) was added iron powder (229 mg, 4.08 mmol) portionwise. The resulting mixture was stirred at rt. After 1.5 h, the reaction was filtered through Celite and the filtrate concentrated in vacuo. The residue was diluted with EtOAc and the resulting organic layer was washed with sat. NaHCO3 and brine. The organic layer was concentrated in vacuo to yield tert-butyl 6-aminoindoline-1-carboxylate as a grey solid. MS (ES+): m/z 235 [M+1]. 1H NMR (CDCl3, 400 MHz): δ1.55 (s, 9H), 2.96 (t, J=8.4 Hz, 2H), 3.61 (br.s, 2H), 3.93 (t, J=8.4 Hz, 2H), 6.27 (d, J=8.4 Hz, 1H), 6.89 (d, J=8.4 Hz, 1H), 7.30 (s, 1H).

Workup

  1. filtrationthe reaction was filtered through Celite
  2. concentrationthe filtrate concentrated in vacuo
  3. additionThe residue was diluted with EtOAc
  4. washthe resulting organic layer was washed with sat. NaHCO3 and brine
  5. concentrationThe organic layer was concentrated in vacuo

Sources & evidence

ORD record
ord-6d75162b0b354fd2b2e7d5615691eda3
Source dataset
uspto-grants-2010_11
Patent number
US07829717B2

Reaction notes

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