3-Cyclopropoxy-2-nitrobenzoic acid → 2-Amino-3-cyclopropoxybenzoic acid

HRID 2276867Notes

Reaction equation

HRID 2276867 reaction equation
[CH:1]1([O:4][C:5]2[C:6]([N+:14]([O-])=O)=[C:7]([CH:11]=[CH:12][CH:13]=2)[C:8]([OH:10])=[O:9])[CH2:3][CH2:2]1>[Pd].CO>[NH2:14][C:6]1[C:5]([O:4][CH:1]2[CH2:2][CH2:3]2)=[CH:13][CH:12]=[CH:11][C:7]=1[C:8]([OH:10])=[O:9]

Participants

4

Reactant 1

HCID 900721183-Cyclopropoxy-2-nitrobenzoic acid

Product 1

HCID 722309382-Amino-3-cyclopropoxybenzoic acidYield 99%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

A 50 mL round bottom flask was charged with 3-cyclopropoxy-2-nitrobenzoic acid (205 mg, 0.919 mmol), 10% Pd/C (25 mg, 0.919 mmol) and methanol (6 mL). The flask was vacuum flushed with nitrogen (3×) followed by a vacuum flush with a hydrogen balloon (3×). The resulting suspension was stirred under a balloon of hydrogen at room temperature over night. The solution was filtered through CELITE®, washing with methanol, and the filtrate was concentrated to provide reddish oil. The crude material was azeotroped with toluene (2×), and dried under vacuum to provide crude 2-amino-3-cyclopropoxybenzoic acid (175 mg, 0.906 mmol, 99% yield) as a reddish solid. The product was used without further purification in the next reaction. HPLC: RT=2.31 min (H2O/MeOH with TFA, SunFire C18 3.5 μm, 2.1×30 mm, gradient=4 min, wavelength=220 nm); MS(ES): m/z=194.12 [M+H]+.

Workup

  1. customflushed with nitrogen (3×)
  2. customflush with a hydrogen balloon (3×)
  3. filtrationThe solution was filtered through CELITE®
  4. washwashing with methanol
  5. concentrationthe filtrate was concentrated
  6. customto provide reddish oil
  7. customThe crude material was azeotroped with toluene (2×)
  8. customdried under vacuum

Sources & evidence

ORD record
ord-cf751679f489459caa744c81a8b643a4
Source dataset
uspto-grants-2015_09
Patent number
US09133139B2

Reaction notes

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