4-Aminophenol → (Z)-4-((4-Hydroxyphenyl)amino)-4-oxobut-2-enoic acid

HRID 224231Notes

Reaction equation

HRID 224231 reaction equation
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.[CH:8]1[C:13]([NH2:14])=[CH:12][CH:11]=[C:10]([OH:15])[CH:9]=1>CN(C)C=O>[OH:15][C:10]1[CH:11]=[CH:12][C:13]([NH:14][C:4](=[O:5])/[CH:3]=[CH:2]\[C:1]([OH:6])=[O:7])=[CH:8][CH:9]=1

Participants

4

Reactant 2

HCID 4034-AminophenolHCID 7923Maleic Anhydride

Product 1

HCID 1550903(Z)-4-((4-Hydroxyphenyl)amino)-4-oxobut-2-enoic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

In a reactor, 50 ml of dimethylformamide and 21.6 g (0.22 moles) of maleic anhydride were placed, to which were gradually added 21.8 g (0.20 moles) of p-aminophenol at 20° C. with thorough stirring. After completion of the addition, the reaction was allowed to proceed at 20° C. for 2 hours to yield N-(p-hydroxyphenyl) maleamic acid. To the reaction mixture, a previously formed solution containing 70 ml of dimethylformamide, 11.4 g (0.0803 moles) of phosphorus pentoxide and 5 g (0.049 moles) of sulfuric acid, was added dropwise with the use of a dropping funnel. Thereafter, the reaction was continued at 70° C. for 2 hours. After cooling to room temperature, the resulting reaction mixture was poured into 400 ml of ice water to precipitate N-(p-hydroxyphenyl) maleimide in the form of crystals. The crystals were separated by filtration, washed with water and then dried to obtain 31.3 g (0.165 moles) of N-(p-hydroxyphenyl) maleimide (yield 82.5%).

Workup

  1. customat 20° C.
  2. additionAfter completion of the addition

Sources & evidence

ORD record
ord-2b3b6685467542f3872c216c7179e0c3
Source dataset
uspto-grants-1980_11
Patent number
US04231934

Reaction notes

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