Trifluoroacetic anhydride → 7-Bromo-1H-indole-3-carboxylic acid

HRID 1174529Notes

Reaction equation

HRID 1174529 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:10]=1[NH:9][CH:8]=[CH:7]2.FC(F)(F)[C:13]([O:15]C(=O)C(F)(F)F)=[O:14]>CN(C)C=O>[Br:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:10]=1[NH:9][CH:8]=[C:7]2[C:13]([OH:15])=[O:14]

Participants

4

Reactant 2

HCID 9845Trifluoroacetic anhydrideHCID 27570207-Bromoindole

Product 1

HCID 248204637-Bromo-1H-indole-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 7-bromoindole (10 g, 51.0 mmol) in N,N-dimethylformamide (DMF) (100 cm3) was added trifluoroacetic anhydride (12.5 cm3, 89.6 mmol) over 5 min. The resultant solution was stirred at room temperature for 16 h. The solution was poured onto water (500 cm3) and the precipitate formed was isolated by filtration, washed with water and 4N sodium hydroxide (200 cm3) added. The suspension was heated at reflux for 1.5 h and allowed to cool before washing with diethyl ether (2×250 cm3). The aqueous layer was acidified to pH 1 with 5N hydrochloric acid and the resultant precipitate isolated by filtration, washed with water and dried over phosphorous pentoxide under reduced pressure at 60° C. for 16 h. This afforded the title compound LA) (8.94 g, 73%).

Workup

  1. additionThe solution was poured onto water (500 cm3)
  2. customthe precipitate formed
  3. customwas isolated by filtration
  4. washwashed with water and 4N sodium hydroxide (200 cm3)
  5. additionadded
  6. temperatureThe suspension was heated
  7. temperatureat reflux for 1.5 h
  8. temperatureto cool
  9. washbefore washing with diethyl ether (2×250 cm3)

Sources & evidence

ORD record
ord-4e44a8f5229c43a893e1376bebc6689c
Source dataset
uspto-grants-2010_11
Patent number
US07838518B2

Reaction notes

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