Ammonium Chloride → Oxybuprocaine Impurity 4

HRID 417304Notes

Reaction equation

HRID 417304 reaction equation
[CH2:1]([O:5][C:6]1[CH:7]=[C:8]([CH:13]=[CH:14][C:15]=1[N+:16]([O-])=O)[C:9]([O:11][CH3:12])=[O:10])[CH2:2][CH2:3][CH3:4].[NH4+].[Cl-]>CO.[Zn]>[CH3:12][O:11][C:9](=[O:10])[C:8]1[CH:13]=[CH:14][C:15]([NH2:16])=[C:6]([O:5][CH2:1][CH2:2][CH2:3][CH3:4])[CH:7]=1

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 60451708HCID 60451708, compound

Product 1

HCID 43380148Oxybuprocaine Impurity 4Yield 82%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 887MethanolSolvent

Procedure

A solution of methyl 3-butoxy-4-nitrobenzoate (2.5 g, 9.9 mmol) in methanol (100 mL) was added an aqueous solution (50 mL) of NH4Cl (5.3 g, 99 mmol), followed by activated zinc (Aldrich, 6.5 g, 99 mmol). The reaction mixture was stirred at room temperature for 1 h. The mixture was filtered through a short pad of celite. The mixture was concentrated. The residue was partitioned between ethyl acetate and water. The organic layer was separated, and aqueous layer was extracted with ethyl acetate. The combined organic extract was washed with water, brine, dried over MgSO4, and concentrated to give 4-amino-3-butoxy-benzoic acid methyl ester as a yellow solid (1.8 g, 82%).

Workup

  1. filtrationThe mixture was filtered through a short pad of celite
  2. concentrationThe mixture was concentrated
  3. customThe residue was partitioned between ethyl acetate and water
  4. customThe organic layer was separated
  5. extractionaqueous layer was extracted with ethyl acetate
  6. extractionThe combined organic extract
  7. washwas washed with water, brine
  8. dry with materialdried over MgSO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-43ff1c2d3ffa4f8680200bbbdf429899
Source dataset
uspto-grants-2012_01
Patent number
US08088815B2

Reaction notes

Loading…