Phosphoric Acid → 1H-Indole-6-carboxaldehyde

HRID 1666790Notes

Reaction equation

HRID 1666790 reaction equation
[H-].[K+].Br[C:4]1[CH:12]=[C:11]2[C:7]([CH:8]=[CH:9][NH:10]2)=[CH:6][CH:5]=1.C([Li])(C)(C)C.CN(C)[CH:20]=[O:21].P(=O)(O)(O)O>CCOCC.CCCCCC>[NH:10]1[C:11]2[C:7](=[CH:6][CH:5]=[C:4]([CH:20]=[O:21])[CH:12]=2)[CH:8]=[CH:9]1

Participants

8

Reactant 5

HCID 1004Phosphoric AcidHCID 6228DimethylformamideHCID 82127Potassium hydrideHCID 6764936-BromoindoleHCID 178418306HCID 178418306, compound

Product 1

HCID 27734351H-Indole-6-carboxaldehyde

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent3×HCID 8058HexaneSolvent2×

Conditions

Temperature
0 °C

Procedure

Combine hexane washed potassium hydride (1.3 g, 10.7 mmol) and ether (20 ml). Cool to about 0° C. and add a solution of 6-bromo-1H-indole (2.1 g, 10.7 mmol) in ether (5 ml). After 15 min, cool to about −78° C. and add a solution of t-butyllithium, 1.4 M solution in hexane (14.0 ml, 10.7 mmol). After 10 min, add dimethylformamide (1.7 ml, 20.0 mmol) in ether (5 ml). Slowly, warm to room temperature and then pour into a ice cold solution of 1M phosphoric acid and extract with EtOAc. Combine the organic layers and wash sequentially with distilled water and brine and then dry (Na2SO4), filter, and concentrated to give a residue. Chromatograph the residue eluting with 9:1 hexane:EtOAc to give the title compound.

Workup

  1. temperaturecool to about −78° C.
  2. waitAfter 10 min
  3. temperatureSlowly, warm to room temperature
  4. extractionextract with EtOAc
  5. washwash sequentially with distilled water and brine
  6. dry with materialdry (Na2SO4)
  7. filtrationfilter
  8. concentrationconcentrated
  9. customto give a residue
  10. washChromatograph the residue eluting with 9:1 hexane

Sources & evidence

ORD record
ord-2fb4cd3759674acf957a2a4420ad9618
Source dataset
uspto-grants-2011_10
Patent number
US08044090B2

Reaction notes

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