Sodium Dithionite → Methyl 2-amino-5-(benzyloxy)-4-methoxybenzoate

HRID 871419Notes

Reaction equation

HRID 871419 reaction equation
[CH2:1]([O:8][C:9]1[C:10]([O:22][CH3:23])=[CH:11][C:12]([N+:19]([O-])=O)=[C:13]([CH:18]=1)[C:14]([O:16][CH3:17])=[O:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[O-]S(S([O-])=O)=O.[Na+].[Na+]>CO.O>[NH2:19][C:12]1[CH:11]=[C:10]([O:22][CH3:23])[C:9]([O:8][CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[CH:18][C:13]=1[C:14]([O:16][CH3:17])=[O:15]

Participants

5

Reactant 2

HCID 24489Sodium DithioniteHCID 22667156Methyl 5-Benzyloxy-4-methoxy-2-nitrobenzoate

Product 1

HCID 22667093Methyl 2-amino-5-(benzyloxy)-4-methoxybenzoate

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution of methyl 5-(benzyloxy)-4-methoxy-2-nitrobenzoate (13.48 g, 0.0425 mol) in MeOH (700 mL) at 55° C., a concentrated solution of Na2S2O4 in water was added slowly until no more starting material was observed on TLC. The heterogeneous solution was concentrated under vacuum. The residue was treated with water (100 ml) and the mixture extracted with ethyl acetate (2×200 mL). The combined organic layers were washed with water and brine. After drying over MgSO4, the solvent was evaporated and the residue was purified on silica gel column, using ethyl acetate/DCM (1/9) as eluent to yield methyl 2-amino-5-(benzyloxy)-4-methoxybenzoate. Yield: 7.36 g (60%). 1HNMR (DMSO-d6): δ 7.34 (5H, m), 7.25 (1H, s), 6.48 (2H, s), 6.39 (1H, s), 4.91 (2H, s), 3.80 (3H, s), 3.73 (3H, s). LC-MS (ESI) m/z 288 (M+H)+.

Workup

  1. concentrationThe heterogeneous solution was concentrated under vacuum
  2. additionThe residue was treated with water (100 ml)
  3. extractionthe mixture extracted with ethyl acetate (2×200 mL)
  4. washThe combined organic layers were washed with water and brine
  5. dry with materialAfter drying over MgSO4
  6. customthe solvent was evaporated
  7. customthe residue was purified on silica gel column

Sources & evidence

ORD record
ord-5814db51fb2142d694877a89bfd5bd89
Source dataset
uspto-grants-2015_03
Patent number
US08969587B2

Reaction notes

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