2-Aminophenol → 1-(2-Hydroxyphenyl)-1H-pyrrole-2,5-dione

HRID 649606Notes

Reaction equation

HRID 649606 reaction equation
C1(=O)OC(=O)C=C1.NC1C=CC=CC=1O.CN(C)C=O.[OH:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][C:23]=1[NH:28][C:29](=[O:35])/[CH:30]=[CH:31]\[C:32]([OH:34])=O>C1(C)C(C)=CC=CC=1.C1(C)C=CC=CC=1>[OH:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][C:23]=1[N:28]1[C:29](=[O:35])[CH:30]=[CH:31][C:32]1=[O:34]

Participants

7

Reactant 4

HCID 58012-AminophenolHCID 6228DimethylformamideHCID 7923Maleic Anhydride2×HCID 1550203(2Z)-4-[(2-Hydroxyphenyl)amino]-4-oxo-2-butenoic acid

Product 1

HCID 7932261-(2-Hydroxyphenyl)-1H-pyrrole-2,5-dione

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 7237O-XyleneSolvent

Procedure

A maleic anhydride copolymer and an aminophenol are heated in an organic solvent such as dimethylformamide to 0°-150° C., preferably 10°-100° C., more preferably 50°-100° C. for 1-20 hours to convert a portion or whole of the maleic anhydride units into N-(hydroxyphenyl)maleamic acid unit. To the reaction mixture is added a tertiary amine catalyst, and is further added an azeotropic agent (i.e., azeotropic solvent) such as toluene or xylene for removing water produced upon cyclization-dehydration reaction. The resulting mixture is then heated to 80°-200° C., preferably 100°-150° C., for 1-20 hours for performing a cyclization-dehydration reaction, to obtain the desired N-(hydroxyphenyl)maleimide copolymer.

Workup

  1. customfor removing water
  2. customproduced upon cyclization-dehydration reaction
  3. temperatureThe resulting mixture is then heated to 80°-200° C., preferably 100°-150° C., for 1-20 hours
  4. customa cyclization-dehydration reaction

Sources & evidence

ORD record
ord-75307692132646ee82769b8fb17624f7
Source dataset
uspto-grants-1988_04
Patent number
US04740561

Reaction notes

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