Sodium Dithionite → tert-Butyl 2-(4-amino-2-chlorophenoxy)ethyl(2,4-difluorobenzyl)carbamate

HRID 1019738Notes

Reaction equation

HRID 1019738 reaction equation
[Cl:1][C:2]1[CH:27]=[C:26]([N+:28]([O-])=O)[CH:25]=[CH:24][C:3]=1[O:4][CH2:5][CH2:6][N:7]([CH2:15][C:16]1[CH:21]=[CH:20][C:19]([F:22])=[CH:18][C:17]=1[F:23])[C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11].S(S([O-])=O)([O-])=O.[Na+].[Na+]>C(O)C>[NH2:28][C:26]1[CH:25]=[CH:24][C:3]([O:4][CH2:5][CH2:6][N:7]([CH2:15][C:16]2[CH:21]=[CH:20][C:19]([F:22])=[CH:18][C:17]=2[F:23])[C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:11])[CH3:12])=[C:2]([Cl:1])[CH:27]=1

Participants

4

Reactant 2

HCID 24489Sodium DithioniteHCID 67468967Tert-butyl 2-(2-chloro-4-nitrophenoxy)ethyl(2,4-difluorobenzyl)carbamate

Product 1

HCID 67469270tert-Butyl 2-(4-amino-2-chlorophenoxy)ethyl(2,4-difluorobenzyl)carbamateYield 95.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of tert-butyl 2-(2-chloro-4-nitrophenoxy)ethyl-(2,4-difluorobenzyl)-carbamate (1.8 g, 4.06 mmol) in 70% aqueous ethanol (30 mL) was added sodium dithionite (2.87 g, 16.25 mmol), and the reaction mixture was heated to reflux for 3 hours. The hot reaction mixture was filtered and the residue washed with EtOAc (30 mL). The combined organic extracts were washed with brine (2×20 mL), dried (Na2SO4) and concentrated to give the title product (1.6 g, 95%) which was used in the next step without further purification.

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureto reflux for 3 hours
  3. filtrationThe hot reaction mixture was filtered
  4. washthe residue washed with EtOAc (30 mL)
  5. washThe combined organic extracts were washed with brine (2×20 mL)
  6. dry with materialdried (Na2SO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-276b88f681754e2ab0709f40ff7ba863
Source dataset
uspto-grants-2014_05
Patent number
US08716287B2

Reaction notes

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