Ammonium Chloride → 2-tert-Butoxycarbonylamino-3-fluorobenzoic acid 2-hydroxyethyl ester

HRID 558980Notes

Reaction equation

HRID 558980 reaction equation
[Si]([O:8][CH2:9][CH2:10][O:11][C:12](=[O:28])[C:13]1[CH:18]=[CH:17][CH:16]=[C:15]([F:19])[C:14]=1[NH:20][C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])(C(C)(C)C)(C)C.[F-].C([N+](CCCC)(CCCC)CCCC)CCC.[Cl-].[NH4+]>C1COCC1>[OH:8][CH2:9][CH2:10][O:11][C:12](=[O:28])[C:13]1[CH:18]=[CH:17][CH:16]=[C:15]([F:19])[C:14]=1[NH:20][C:21]([O:23][C:24]([CH3:26])([CH3:25])[CH3:27])=[O:22]

Participants

5

Reactant 3

HCID 25517Ammonium ChlorideHCID 2724141Tetrabutylammonium FluorideHCID 669995852-tert-Butoxycarbonylamino-3-fluorobenzoic acid 2-(tert-butyldimethylsilanyloxy)ethyl ester

Product 1

HCID 669999872-tert-Butoxycarbonylamino-3-fluorobenzoic acid 2-hydroxyethyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 2-tert-butoxycarbonylamino-3-fluorobenzoic acid 2-(tert-butyldimethylsilanyloxy)ethyl ester from Example 19B (1.2 g, 2.9 mmol) in THF (25 ml) was added a solution tetrabutylammonium fluoride (1.0M, 5.8 ml, 5.8 mmol) in THF while cooling in an ice/water bath. The mixture was allowed to warm to room temperature and stirred for 18 h. Saturated ammonium chloride solution (20 ml) was added and the mixture was stirred for 1 h and evaporated in vacuo. The residue was partitioned between chloroform and water and the organic phase was dried and evaporated in vacuo. The residue was purified by flash chromatography on silica (eluant EtOAc:pet.ether 90:10) to give a colourless gum; yield 180 mg, 21%.

Workup

  1. temperaturewhile cooling in an ice/water bath
  2. stirringthe mixture was stirred for 1 h
  3. customevaporated in vacuo
  4. customThe residue was partitioned between chloroform and water
  5. customthe organic phase was dried
  6. customevaporated in vacuo
  7. customThe residue was purified by flash chromatography on silica (eluant EtOAc:pet.ether 90:10)
  8. customto give a colourless gum

Sources & evidence

ORD record
ord-7723bc37ca0c4228b3bb6b5803c3c8c2
Source dataset
uspto-grants-2011_11
Patent number
US08063038B2

Reaction notes

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