Water → 4-Chloroisatoic anhydride

HRID 2288016Notes

Reaction equation

HRID 2288016 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([NH2:11])[C:5](=[CH:9][CH:10]=1)[C:6]([OH:8])=[O:7].O.[C:13](Cl)(Cl)=[O:14]>C1(C)C=CC=CC=1>[Cl:1][C:2]1[CH:10]=[CH:9][C:5]2[C:6](=[O:8])[O:7][C:13](=[O:14])[NH:11][C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 962WaterHCID 6371PhosgeneHCID 666462-Amino-4-chlorobenzoic acid2×

Product 1

HCID 3291054-Chloroisatoic anhydrideYield 93%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

4-Chloroanthranilic acid (10.0 g, 56.5 mmol) was dissolved at room temperature with stirring in 190 mL of distilled water containing 8.98 g (84.7 mmol) Na2CO3. When the 4-chloroanthranilic acid was completely dissolved, a 20% w/v solution of phosgene in toluene (84 mL) was added dropwise via a dropping funnel over 45 minutes. The resulting suspension was stirred at room temperature overnight under nitrogen. The product was collected by filtration and washed well with water. The resulting gray-white solid was dried in a vacuum oven at 60° C. overnight to provide 7-chloro-1,4-dihydro-2H-3,1-benzoxazine-2,4-dione (10.3 g, 52.3 mmol, 93%): 1H NMR (DMSO-d6): δ 11.93 (br s, 1H), 7.17 (d, J=1.5 Hz, 1H), 7.28 (dd, J=1.6 and 8.2 Hz, 1H), 7.91 (d, J=8.2 Hz, 1H).

Workup

  1. filtrationThe product was collected by filtration
  2. washwashed well with water
  3. customThe resulting gray-white solid was dried in a vacuum oven at 60° C. overnight

Sources & evidence

ORD record
ord-2c792688acfa4ce083daaf5c75df94d4
Source dataset
uspto-grants-2000_07
Patent number
US06087368

Reaction notes

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