Hydrochloric Acid → 3-Hydroxy-2-nitrobenzoic acid

HRID 921259

Reaction equation

HRID 921259 reaction equation
Cl[C:2]1[C:3]([N+:11]([O-:13])=[O:12])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6].[OH-].[K+].Cl.C(O)(C(F)(F)F)=[O:18]>O.O.CO>[OH:18][C:2]1[C:3]([N+:11]([O-:13])=[O:12])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6422Trifluoroacetic acidHCID 14797Potassium HydroxideHCID 209023-Chloro-2-nitrobenzoic acid

Product 1

HCID 2932913-Hydroxy-2-nitrobenzoic acidYield 66%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 22242641Methanol--water (1/1)Solvent

Procedure

To a 250 mL flask were added 3-chloro-2-nitrobenzoic acid (10 g, 49.6 mmol) and a potassium hydroxide solution (40 g, 727 mmol) in water (70 mL). The thick slurry was heated to reflux for 12 hours. The solution was cooled in ice and cautiously brought to pH 3 with concentrated HCl. The aqueous mixture was extracted with EtOAc (3×). The organic layers were combined, washed with brine, dried with sodium sulfate and concentrated in vacuo. The crude product mixture was dissolved in dichloromethane and the resulting yellow precipitate was filtered to afford Intermediate A-15A (6 g, 32.8 mmol, 66.0% yield). HPLC: RT=0.85 min (H2O/MeOH with TFA, Sunfire C18 3.5 μm, 2.1×30 mm, gradient=4 min, wavelength=220 nm); MS(ES): m/z=206 [M+Na]+; 1H NMR (400 MHz, chloroform-d) δ 7.56-7.35 (m, 1H), 7.23 (dd, J=7.9, 1.5 Hz, 1H).

Workup

  1. temperatureThe thick slurry was heated
  2. temperatureto reflux for 12 hours
  3. temperatureThe solution was cooled in ice
  4. extractionThe aqueous mixture was extracted with EtOAc (3×)
  5. washwashed with brine
  6. dry with materialdried with sodium sulfate
  7. concentrationconcentrated in vacuo
  8. dissolutionThe crude product mixture was dissolved in dichloromethane
  9. filtrationthe resulting yellow precipitate was filtered
  10. customto afford Intermediate A-15A (6 g, 32.8 mmol, 66.0% yield)

Sources & evidence

ORD record
ord-3861fac199d341acb9eafdea11cafeca
Source dataset
uspto-grants-2016_03
Patent number
US09273014B2

Linked notes

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