5-Chloroisatoic anhydride → Methyl 2-amino-5-chlorobenzoate

HRID 2244348Notes

Reaction equation

HRID 2244348 reaction equation
[Cl:1][C:2]1[CH:13]=[CH:12][C:5]2[NH:6][C:7](=O)[O:8][C:9](=[O:10])[C:4]=2[CH:3]=1>CO.CN(C1C=CN=CC=1)C>[CH3:7][O:8][C:9](=[O:10])[C:4]1[CH:3]=[C:2]([Cl:1])[CH:13]=[CH:12][C:5]=1[NH2:6]

Participants

4

Reactant 1

HCID 784805-Chloroisatoic anhydride

Product 1

HCID 78878Methyl 2-amino-5-chlorobenzoateYield 98.5%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 887MethanolSolvent

Procedure

To a suspension of 6-chloro-1H-benzo[d][1,3]oxazine-2,4-dione (10 g, 50.61 mmol) in methanol (200 ml) was added DMAP (615 mg, 5.03 mmol) and the reaction mixture was heated to reflux for 3 h. The reaction mixture was cooled to RT and concentrated in vacuo. The residue was dissolved in EtOAc and washed with 0.1M HCl solution (3×), brine, dried over MgSO4, filtered and concentrated in vacuo to give the desired product (9.25 g, 97%) as a white solid which did not require further purification. 1H NMR (DMSO-d6, 300 MHz): δ 7.64 (d, J=2.5 Hz, 1H), 7.30 (dd, J=2.5 and 9.0 Hz, 1H), 6.82 (d, J=9.0 Hz, 1H), 6.78 (br s, 2H), 3.79 (s, 3H).

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureto reflux for 3 h
  3. concentrationconcentrated in vacuo
  4. dissolutionThe residue was dissolved in EtOAc
  5. washwashed with 0.1M HCl solution (3×), brine
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-a00a0dec39f240bc85972439e175f94b
Source dataset
uspto-grants-2010_03
Patent number
US07678818B2

Reaction notes

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