Pyridine → 5-Bromoisatoic Anhydride

HRID 1295450Notes

Reaction equation

HRID 1295450 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:8]([Br:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].N1C=CC=CC=1.Cl[C:19](Cl)([O:21]C(=O)OC(Cl)(Cl)Cl)Cl>C(#N)C.ClCCl>[Br:11][C:8]1[CH:9]=[CH:10][C:2]2[NH:1][C:19](=[O:21])[O:5][C:4](=[O:6])[C:3]=2[CH:7]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 798582-Amino-5-bromobenzoic acidHCID 94429Triphosgene

Product 1

HCID 2885615-Bromoisatoic AnhydrideYield 292.1%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Procedure

A solution of 2-amino-5-bromo-benzoic acid (280 g, 1.3 mol) in acetonitrile (1.3 l) was warmed up to 50–55° C. Pyridine (206 g, 2.61 mol) and a solution of triphosgene (128.8 g, 0.43 mol) in dichloromethane (720 ml) were simultaneously added dropwise. After completion of the addition, the mixture was stirred at 50–55° C. for an additional 2 h. The solvent was removed under reduced pressure and water was added. The precipitate was collected by filtration, successively washed with water and chilled dichloromethane, and then dried under vacuum to afford the desired product 6-bromo-1H-benzo[d][1,3]oxazine-2,4-dione (304 g, 98%). This material was used in the next step without further purification.

Workup

  1. additionAfter completion of the addition
  2. customThe solvent was removed under reduced pressure and water
  3. additionwas added
  4. filtrationThe precipitate was collected by filtration
  5. washsuccessively washed with water
  6. temperaturechilled dichloromethane
  7. customdried under vacuum

Sources & evidence

ORD record
ord-b076974f4cab440cb9c009e16b209ca3
Source dataset
uspto-grants-2007_07
Patent number
US07241893B2

Reaction notes

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