Cornforth reagent → 1H-Indole-6-carboxaldehyde

HRID 1198556Notes

Reaction equation

HRID 1198556 reaction equation
[OH:1][CH2:2][C:3]1[CH:11]=[C:10]2[C:6]([CH:7]=[CH:8][NH:9]2)=[CH:5][CH:4]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl.C(OCC)C>[CH:2]([C:3]1[CH:11]=[C:10]2[C:6]([CH:7]=[CH:8][NH:9]2)=[CH:5][CH:4]=1)=[O:1]

Participants

5

Reactant 2

HCID 2724130Cornforth reagentHCID 27734596-Hydroxymethylindole

Product 1

HCID 27734351H-Indole-6-carboxaldehyde

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 6-hydroxymethyl indole (4.9 g, 33.3 mmol) in dry dichloromethane (200 ml) was added a solution of pyridinium dichromate (15.97 g, 42.5 mmol) in dry dichloromethane (100 ml) and the suspension stirred at room temperature for 5 hours. The suspension was diluted with diethyl ether and filtered through a pad of silica to give an orange solution, which was evaporated in vacuo. The crude solid was purified by flash chromatography on silica, eluting with 50% diethyl ether in hexane, to yield a pale orange solid. Recrystallisation from diethyl ether/40°-60° C. petrol gave a pale orange crystalline solid, m.p. 126°-128° C.

Workup

  1. filtrationfiltered through a pad of silica
  2. customto give an orange solution, which
  3. customwas evaporated in vacuo
  4. customThe crude solid was purified by flash chromatography on silica
  5. washeluting with 50% diethyl ether in hexane
  6. customto yield a pale orange solid
  7. customRecrystallisation from diethyl ether/40°-60° C. petrol
  8. customgave a pale orange crystalline solid, m.p. 126°-128° C.

Sources & evidence

ORD record
ord-81d129acc59146c593c8fbf2aac518ba
Source dataset
uspto-grants-1994_01
Patent number
US05281593

Reaction notes

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