Lithium hydroxide, monohydrate → 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylic acid

HRID 661895Notes

Reaction equation

HRID 661895 reaction equation
[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15](=[O:17])[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH:5]=[CH:6][C:7]([C:18]([O:20]CC)=[O:19])=[CH:8][C:9]=1[NH:10]2.O.[OH-].[Li+]>C1COCC1.C(O)C.O>[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15](=[O:17])[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH:5]=[CH:6][C:7]([C:18]([OH:20])=[O:19])=[CH:8][C:9]=1[NH:10]2

Participants

4

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 59375100ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylate2×

Product 1

HCID 593750825-bromo-8-carbamoyl-9H-carbazole-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 18504229Ethanol tetrahydrofuran waterSolvent

Procedure

A suspension of ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylate (Intermediate 48-1, 1.81 g, 5.01 mmol) and lithium hydroxide monohydrate (0.601 g, 15.03 mmol) in THF-ethanol-water (3:1:1, 50 mL) was heated at reflux for 2 h. The mixture was cooled to rt and concentrated. The residue was stirred in water and treated with 1 M hydrochloric acid to pH 1-2. The precipitate was collected by filtration, washed with water, and dried to afford 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylic acid as a light brown solid (1.84 g, ca. 90% purity, 99%). 1H NMR (400 MHz, DMSO-d6) δ 12.95 (br. s., 1H) 12.02 (s, 1H) 8.69 (d, J=8.53 Hz, 1H) 8.47 (s, 1H) 8.28 (br. s., 1H) 7.94 (d, J=8.28 Hz, 2H) 7.87 (d, J=8.28 Hz, 1H) 7.65 (br. s., 1H) 7.51 (d, J=8.03 Hz, 1H). Mass spectrum m/z 331, 333 (M−H)−.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 2 h
  3. concentrationconcentrated
  4. additiontreated with 1 M hydrochloric acid to pH 1-2
  5. filtrationThe precipitate was collected by filtration
  6. washwashed with water
  7. customdried

Sources & evidence

ORD record
ord-51cb03a698254164811e2dbbb1ca4e86
Source dataset
uspto-grants-2011_12
Patent number
US08084620B2

Reaction notes

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