Ethanol → 2-Tert-butyl-5-nitro-1H-indole-7-carboxylic acid

HRID 1908436Notes

Reaction equation

HRID 1908436 reaction equation
[C:1]([C:5]1[NH:6][C:7]2[C:12]([CH:13]=1)=[CH:11][C:10]([N+:14]([O-:16])=[O:15])=[CH:9]C=2C#N)([CH3:4])([CH3:3])[CH3:2].[OH-:19].[K+].[CH3:21][CH2:22][OH:23]>>[C:1]([C:5]1[NH:6][C:7]2[C:12]([CH:13]=1)=[CH:11][C:10]([N+:14]([O-:16])=[O:15])=[CH:9][C:21]=2[C:22]([OH:19])=[O:23])([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 3

HCID 702EthanolHCID 14797Potassium HydroxideHCID 534211842-Tert-butyl-5-nitro-1H-indole-7-carbonitrile

Product 1

HCID 534211852-Tert-butyl-5-nitro-1H-indole-7-carboxylic acidYield 77%

Procedure

2-tert-Butyl-5-nitro-1H-indole-7-carbonitrile (4.6 g, 19 mmol) was added to a solution of KOH in EtOH (10%, 100 mL) and the mixture was heated at reflux overnight. The solution was evaporated to remove alcohol, a small amount of water was added, and then the mixture was acidified with dilute hydrochloric acid. Upon standing in the refrigerator, an orange-yellow solid precipitated, which was purified by chromatography on silica gel (15% EtOAc in petroleum ether) to afford 2-tert-butyl-5-nitro-1H-indole-7-carboxylic acid (4.0 g, 77%). 1H NMR (CDCl3, 300 MHz) δ 10.79 (brs, 1H), 8.66 (s, 1H), 8.45 (s, 1H), 6.57 (s, 1H), 1.39 (s, 9H).

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux overnight
  3. customThe solution was evaporated
  4. customto remove alcohol
  5. additiona small amount of water was added
  6. customan orange-yellow solid precipitated
  7. customwhich was purified by chromatography on silica gel (15% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-d13bb39739ed40799f5c040d27d87226
Source dataset
uspto-grants-2013_12
Patent number
US08598181B2

Reaction notes

Loading…