Lithium Hydroxide → 8-(2,6-Difluoro-3,5-dimethoxy-phenyl)quinoxaline-5-carboxylic acid

HRID 1189908Notes

Reaction equation

HRID 1189908 reaction equation
C([O:3][C:4]([C:6]1[C:7]2[N:8]=[CH:9][CH:10]=[N:11][C:12]=2[C:13]([C:16]2[C:21]([F:22])=[C:20]([O:23][CH3:24])[CH:19]=[C:18]([O:25][CH3:26])[C:17]=2[F:27])=[CH:14][CH:15]=1)=[O:5])C.[Li+].[OH-]>C1COCC1>[F:22][C:21]1[C:20]([O:23][CH3:24])=[CH:19][C:18]([O:25][CH3:26])=[C:17]([F:27])[C:16]=1[C:13]1[C:12]2[N:11]=[CH:10][CH:9]=[N:8][C:7]=2[C:6]([C:4]([OH:5])=[O:3])=[CH:15][CH:14]=1

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 866411458-(2,6-Difluoro-3,5-dimethoxyphenyl)quinoxaline-5-carboxylic acid ethyl ester

Product 1

HCID 592928348-(2,6-Difluoro-3,5-dimethoxy-phenyl)quinoxaline-5-carboxylic acidYield 85.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 8-(2,6-difluoro-3,5-dimethoxy-phenyl)-quinoxaline-5-carboxylic acid ethyl ester (885 mg, 2.37 mmol) (Step 185.2), a 2N aqueous solution of LiOH (8 mL) and THF (8 mL) was stirred for 16 h at rt. THF was removed under vacuum. The resulting mixture was diluted with Et2O/H2O. The aqueous layer was separated and extracted with Et2O. The aqueous layer was acidified to pH 6 by addition of a 2N aqueous solution of HCl. The resulting yellow precipitate was collected by vacuum filtration and dried to provide 701 mg of the title compound: ESI-MS: 347 [M+H]+; tR=3.16 min (System 1)

Workup

  1. customTHF was removed under vacuum
  2. additionThe resulting mixture was diluted with Et2O/H2O
  3. customThe aqueous layer was separated
  4. extractionextracted with Et2O
  5. additionThe aqueous layer was acidified to pH 6 by addition of a 2N aqueous solution of HCl
  6. filtrationThe resulting yellow precipitate was collected by vacuum filtration
  7. customdried

Sources & evidence

ORD record
ord-61f7ce3459b34754bbe538e53c85d94e
Source dataset
uspto-grants-2014_03
Patent number
US08674099B2

Reaction notes

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