Ethyl 5-nitro-1H-indole-2-carboxylate → Ethyl 5-amino-1H-indole-2-carboxylate

HRID 606589Notes

Reaction equation

HRID 606589 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([N+:15]([O-])=O)=[CH:10][CH:9]=2)=[O:5])[CH3:2].C([O-])(=O)C.[NH4+].C(=O)([O-])O.[Na+]>CC(C)=O.[Cl-].[Ti+3].[Cl-].[Cl-]>[CH2:1]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([NH2:15])=[CH:10][CH:9]=2)=[O:5])[CH3:2]

Participants

6

Reactant 3

HCID 280312Ethyl 5-nitro-1H-indole-2-carboxylateHCID 516892Sodium BicarbonateHCID 517165Ammonium Acetate

Product 1

HCID 10726872Ethyl 5-amino-1H-indole-2-carboxylateYield 51.6%

Reagents, catalysts & solvents 2

HCID 10313229titanium(III) trichlorideCatalystHCID 180AcetoneSolvent

Procedure

5-Nitro-1H-indole-2-carboxylic acid ethyl ester (14.9 mmol) was suspended in acetone (50 ml) and added to a mixture of titanium(III) chloride (91 ml, >10% in 2M hydrochloric acid) and ammonium acetate (265 ml, 4M). The reaction was stirred for 2 h and neutralized with saturated sodium hydrogen carbonate. The mixture was extracted with ethyl acetate (100 ml) and the organic layer dried (MgSO4). The solvent was removed in vacuo to give a light brown solid which was purified by silica chromatography to give the title compound as an off-white solid (1.57 g) m/z=205 in MS ES+.

Workup

  1. extractionThe mixture was extracted with ethyl acetate (100 ml)
  2. dry with materialthe organic layer dried (MgSO4)
  3. customThe solvent was removed in vacuo
  4. customto give a light brown solid which
  5. customwas purified by silica chromatography

Sources & evidence

ORD record
ord-9cbcd8381e3a456495257f73325a3613
Source dataset
uspto-grants-2011_03
Patent number
US07915300B2

Reaction notes

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