Potassium Hydroxide → 2-Carbamoyl-1H-indole-5-carboxylic acid

HRID 2403670Notes

Reaction equation

HRID 2403670 reaction equation
[C:1]([C:4]1[NH:5][C:6]2[C:11]([CH:12]=1)=[CH:10][C:9]([C:13]([O:15]C)=[O:14])=[CH:8][CH:7]=2)(=[O:3])[NH2:2].[OH-].[K+]>O1CCCC1.C(O)CO.O>[C:1]([C:4]1[NH:5][C:6]2[C:11]([CH:12]=1)=[CH:10][C:9]([C:13]([OH:15])=[O:14])=[CH:8][CH:7]=2)(=[O:3])[NH2:2]

Participants

6

Reactant 2

HCID 14797Potassium HydroxideHCID 70896052methyl 2-carbamoyl-1H-indole-5-carboxylate

Product 1

HCID 180713662-Carbamoyl-1H-indole-5-carboxylic acidYield 82%

Reagents, catalysts & solvents 3

HCID 174Ethylene GlycolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a suspension of methyl 2-carbamoyl-1H-indole-5-carboxylate (300 mg, 1.38 mmol) in tetrahydrofuran (4.5 mL) and ethylene glycol (4.5 mL) was added potassium hydroxide (3.16 g, 56.4 mmol). The mixture was heated to reflux and stirred for 2 hours. The reaction was cooled to room temperature and diluted with water. The tetrahydrofuran was removed under reduced pressure. The solids were filtered off and the filtrate was acidified to pH 4 with concentrated hydrochloric acid. The resulting precipitate was collected by filtration and dried under vacuum to give 2-carbamoyl-1H-indole-5-carboxylic acid (230 mg, 82%). 1H NMR (400 MHz, DMSO-d6, δ): 12.53 (br. s., 1 H), 11.88 (br. s., 1 H), 8.28 (s, 1 H), 8.04 (br. s., 1 H), 7.77 (d, J=8.6 Hz, 1 H), 7.46 (m, J=8.6 Hz, 2 H), 7.25 (s, 1 H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux
  3. customThe tetrahydrofuran was removed under reduced pressure
  4. filtrationThe solids were filtered off
  5. filtrationThe resulting precipitate was collected by filtration
  6. customdried under vacuum

Sources & evidence

ORD record
ord-3504e90373084e05af1f489294348b0a
Source dataset
uspto-grants-2014_08
Patent number
US08802688B2

Reaction notes

Loading…