p-Toluenesulfonic acid → Methyl 2-chloro-3-nitrobenzoate

HRID 1961773Notes

Reaction equation

HRID 1961773 reaction equation
[Cl:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[CH3:14]C1C=CC(S(O)(=O)=O)=CC=1>CO>[Cl:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:14])=[O:5]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 198702-Chloro-3-nitrobenzoic acid

Product 1

HCID 10751184Methyl 2-chloro-3-nitrobenzoateYield 383.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a suspension of 2-chloro-3-nitrobenzoic acid (100 g, 495 mmol) in MeOH (600 mL) was added TsOH (20 g, 10%). Then the mixture was heated at reflux overnight. The solvent was removed. The residue was diluted with EtOAc (1 L). Then the pH was adjusted to around 9 by progressively adding saturated NaHCO3. The organic layer was separated. The aqueous layer was extracted with EtOAc (1 L×3). The combined organic layers were washed with water and brine successively, dried over Na2SO4, filtered and concentrated under reduced pressure to give the title compound (96 g, 90.6% yield). 1H NMR (400 MHz, CDCl3) δ ppm 7.90 (dd, J=1.8 Hz, 7.9 Hz, 1H), 7.81 (dd, J=1.5 Hz, 7.7 Hz, 1H), 7.45 (dd, J=7.7 Hz, 7.9 Hz, 1H), 3.94 (s, 1H).

Workup

  1. temperatureThen the mixture was heated
  2. temperatureat reflux overnight
  3. customThe solvent was removed
  4. additionThe residue was diluted with EtOAc (1 L)
  5. customThe organic layer was separated
  6. extractionThe aqueous layer was extracted with EtOAc (1 L×3)
  7. washThe combined organic layers were washed with water and brine successively
  8. dry with materialdried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-4f5432eac5134814833c6f453abfa1ea
Source dataset
uspto-grants-2013_04
Patent number
US08415345B2

Reaction notes

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