Indole → Indole-3-Carboxaldehyde

HRID 843268Notes

Reaction equation

HRID 843268 reaction equation
P(Cl)(Cl)(Cl)=O.[NH:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH:8]=[CH:7]1.CN([CH:18]=[O:19])C>>[NH:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8]([CH:18]=[O:19])=[CH:7]1

Participants

4

Reactant 3

HCID 798IndoleHCID 6228DimethylformamideHCID 24813Phosphorus oxychloride

Product 1

HCID 10256Indole-3-CarboxaldehydeYield 90%

Conditions

Temperature
0 °C

Procedure

To a 500 mL round bottom flask containing 250 mL of DMF at 0° C. was added 105 mL (1.12 mol) of phosphorous oxychloride dropwise via an addition funnel. The reaction mixture was stirred for 30 min at 0° C. and then indole (0.51 mol) was added as a solid. The reaction mixture was heated to 80° C. for 6 h and then cooled in an ice bath. The cold solidified reaction was quenched with water (˜2 L) until all the solid had dissolved. The solution was kept cool and the pH was adjusted to ˜11 by the addition of 50% NaOH. The precipitate was filtered and washed with water. The filter cake was dried in vacuo in the presence of P2O5 to yield crude indole-3-carboxaldehyde (90-95% yield).

Workup

  1. temperatureThe reaction mixture was heated to 80° C. for 6 h
  2. temperaturecooled in an ice bath
  3. customreaction
  4. customwas quenched with water (˜2 L) until all the solid
  5. dissolutionhad dissolved
  6. temperatureThe solution was kept cool
  7. additionthe pH was adjusted to ˜11 by the addition of 50% NaOH
  8. filtrationThe precipitate was filtered
  9. washwashed with water
  10. dry with materialThe filter cake was dried in vacuo in the presence of P2O5

Sources & evidence

ORD record
ord-6038c24ac520425280b57e4d50568e36
Source dataset
uspto-grants-2002_04
Patent number
US06376670B1

Reaction notes

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