Hydrochloric Acid → 3-(4-Bromo-phenyl)-pyrrole-2,5-dione

HRID 503029Notes

Reaction equation

HRID 503029 reaction equation
Cl.[Br:2][C:3]1[CH:9]=[CH:8][C:6](N)=[CH:5][CH:4]=1.N([O-])=O.[Na+].[C:14]1(=[O:20])[NH:18][C:17](=[O:19])[CH:16]=[CH:15]1.C([O-])(=O)C.[Na+]>O.CC(C)=O.[Cu](Cl)Cl>[Br:2][C:3]1[CH:9]=[CH:8][C:6]([C:16]2[C:17](=[O:19])[NH:18][C:14](=[O:20])[CH:15]=2)=[CH:5][CH:4]=1

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 78074-BromoanilineHCID 10935MaleimideHCID 517045Sodium AcetateHCID 23668193Sodium Nitrite

Product 1

HCID 198434683-(4-Bromo-phenyl)-pyrrole-2,5-dioneYield 64.2%

Reagents, catalysts & solvents 3

HCID 24014Cupric ChlorideCatalystHCID 180AcetoneSolventHCID 962WaterSolvent2×

Procedure

A solution of hydrochloric acid (37%, 27 mL) in water (11 mL) was added to 4-bromo aniline (15 g) at room temperature with vigorous stirring and the formed precipitate was allowed to stir for further 30 minutes. Temperature was reduced to 0° C. and a solution of sodium nitrite (6.60 g) in water (17 mL) was added dropwise to the stirred suspension. At the end of diazotisation, a clear yellow solution was obtained. Maleimide (16.90 g) in acetone (70 mL) was added dropwise at 0° C. and then the pH of the solution was adjusted to 3-3.5 by adding sodium acetate. Copper (II) chloride (1.76 g) was added to the vigorously stirred mixture. The reaction mixture was allowed to stir at 0° C. for 1 h and overnight at room temperature. Acetone was removed in vacuo, the residue was filtered and dried overnight in vacuo to give the crude title compound (14.12 g) which was used without further purification.

Workup

  1. stirringto stir for further 30 minutes
  2. customwas reduced to 0° C.
  3. customAt the end of diazotisation, a clear yellow solution was obtained
  4. stirringto stir at 0° C. for 1 h and overnight at room temperature
  5. customAcetone was removed in vacuo
  6. filtrationthe residue was filtered
  7. customdried overnight in vacuo

Sources & evidence

ORD record
ord-a0ed9f0fbf124899862bee9254790451
Source dataset
uspto-grants-2010_08
Patent number
US07776904B2

Reaction notes

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