Hydrochloric Acid → 3-[4-(Trifluoromethyl)phenyl]-1H-pyrrole-2,5-dione

HRID 12646

Reaction equation

HRID 12646 reaction equation
Cl.[F:2][C:3]([F:12])([F:11])[C:4]1[CH:10]=[CH:9][C:7](N)=[CH:6][CH:5]=1.N([O-])=O.[Na+].[C:17]1(=[O:23])[NH:21][C:20](=[O:22])[CH:19]=[CH:18]1.C([O-])(=O)C.[Na+]>O.CC(C)=O.[Cu](Cl)Cl>[F:2][C:3]([F:12])([F:11])[C:4]1[CH:10]=[CH:9][C:7]([C:19]2[C:20](=[O:22])[NH:21][C:17](=[O:23])[CH:18]=2)=[CH:6][CH:5]=1

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 99644-(Trifluoromethyl)anilineHCID 10935MaleimideHCID 517045Sodium AcetateHCID 23668193Sodium Nitrite

Product 1

HCID 220268933-[4-(Trifluoromethyl)phenyl]-1H-pyrrole-2,5-dioneYield 69%

Reagents, catalysts & solvents 3

HCID 24014Cupric ChlorideCatalystHCID 180AcetoneSolventHCID 962WaterSolvent2×

Procedure

A mixture of hydrochloric acid (37% in water, 285 mL) and water (190 mL) was added to 4-(trifluoromethyl)aniline (150 g, 116 mL) 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 sodium nitrite (70.6 g) in 180 mL of water was added dropwise to the stirred suspension. At the end of diazotisation, a clear yellow solution was obtained. Maleimide (180 g) in acetone (1.1 L) 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 (18.8 g) was added to the vigorously stirred mixture. After a few minutes a gas started to develop (conspicuous foaming). 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 title compound (155 g) as a light brown solid.

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. waitAfter a few minutes a gas started
  5. stirringto stir at 0° C. for 1 h and overnight at room temperature
  6. customAcetone was removed in vacuo
  7. filtrationthe residue was filtered
  8. customdried overnight in vacuo

Sources & evidence

ORD record
ord-ef3281565b4e4622afcb19c9b901291b
Source dataset
uspto-grants-2010_06
Patent number
US07727988B2

Linked notes

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