Ammonium Chloride → Tert-butyl 4-amino-2-fluorobenzoate

HRID 891458Notes

Reaction equation

HRID 891458 reaction equation
[F:1][C:2]1[CH:14]=[C:13]([N+:15]([O-])=O)[CH:12]=[CH:11][C:3]=1[C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5].[Cl-].[NH4+]>C(O)C.O.[Fe]>[C:7]([O:6][C:4](=[O:5])[C:3]1[CH:11]=[CH:12][C:13]([NH2:15])=[CH:14][C:2]=1[F:1])([CH3:10])([CH3:8])[CH3:9]

Participants

6

Reactant 2

HCID 25517Ammonium ChlorideHCID 10243388Tert-butyl 2-fluoro-4-nitrobenzoate

Product 1

HCID 10058989Tert-butyl 4-amino-2-fluorobenzoateYield 99.9%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 702EthanolSolventHCID 962WaterSolvent

Conditions

Temperature
95 °C

Procedure

Tert-butyl 2-fluoro-4-nitrobenzoate (24.2 g, 0.100 mol) was added to a warm (95° C.) solution of ammonium chloride (53.5 g, 1.00 mol), dissolved in ethanol (300 ml) and water (150 ml). Iron powder (325 mesh, 16.8 g, 0.300 mol) was added with stirring in small portions over ca. 1 h. The reaction mixture was stirred and heated at 95° C. for another 30 minutes and then filtered while still warm. The filter cake was washed thoroughly with excess ethanol. The filtrate and washings were diluted with water (1 L) and extracted with ether (3×150 ml). Combined ether extracts were washed with water and brine, dried (MgSO4), and evaporated to give the product as an off-white solid (21.1 g, 98%); mp 100-101° C. 1H NMR.

Workup

  1. stirringThe reaction mixture was stirred
  2. filtrationfiltered
  3. temperaturewhile still warm
  4. washThe filter cake was washed thoroughly with excess ethanol
  5. additionThe filtrate and washings were diluted with water (1 L)
  6. extractionextracted with ether (3×150 ml)
  7. washCombined ether extracts were washed with water and brine
  8. dry with materialdried (MgSO4)
  9. customevaporated

Sources & evidence

ORD record
ord-862ffcf498d247d3b3f67199f7422b21
Source dataset
uspto-grants-2006_02
Patent number
US07002020B1

Reaction notes

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