2-Methoxy-5-nitrobenzoic acid → 5-Amino-2-methoxybenzoic acid

HRID 1253254Notes

Reaction equation

HRID 1253254 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[CH:10][C:9]([N+:12]([O-])=O)=[CH:8][C:4]=1[C:5]([OH:7])=[O:6].Cl.O1CCOCC1>C(O)(=O)C.[Zn]>[NH2:12][C:9]1[CH:10]=[CH:11][C:3]([O:2][CH3:1])=[C:4]([CH:8]=1)[C:5]([OH:7])=[O:6]

Participants

5

Reactant 2

HCID 2841632-Methoxy-5-nitrobenzoic acidHCID 204431481,4-Dioxane hydrochloride

Product 1

HCID 135492445-Amino-2-methoxybenzoic acidYield 204.9%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalyst2×HCID 176Acetic AcidSolvent

Conditions

Temperature
30 °C

Procedure

Cyclobranyl ester of 2-methoxy-5-nitrobenzoic acid (25.0 g, 0.040 mole) prepared according to the procedure of Example 172 was suspended in acetic acid (1 l), and thereto 6N-HCl-dioxane (21 ml) and zinc powder (25.0 g) were added. The mixture was stirred at 30° C. for 2 hours. After the reaction, zinc powder was removed by filtration. The filtrate was concentrated under reduced pressure, and the residue was extracted with chloroform. The extracts were washed successively with water and saturated aqueous NaHCO3 solution, then dried, concentrated, and the residue was recrystallized from chloroform-ethanol (1:2, v/v), giving cyclobranyl ester of 5-amino-2-methoxybenzoic acid (13.7 g) in a 57.5% yield. m.p. 193°-195° C.

Workup

  1. customwas removed by filtration
  2. concentrationThe filtrate was concentrated under reduced pressure
  3. extractionthe residue was extracted with chloroform
  4. washThe extracts were washed successively with water and saturated aqueous NaHCO3 solution
  5. customdried
  6. concentrationconcentrated
  7. customthe residue was recrystallized from chloroform-ethanol (1:2

Sources & evidence

ORD record
ord-0346f0c4c2e240b389d578dd400785e2
Source dataset
uspto-grants-1988_05
Patent number
US04748161

Reaction notes

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