P-Phenylenediamine → (2Z)-4-[(4-Aminophenyl)amino]-4-oxo-2-butenoic acid
Reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][C:4]([NH2:7])=[CH:3][CH:2]=1.[C:9]1(=[O:15])[O:14][C:12](=[O:13])[CH:11]=[CH:10]1>O1CCCC1>[NH2:7][C:4]1[CH:5]=[CH:6][C:1]([NH:8][C:9](=[O:15])/[CH:10]=[CH:11]\[C:12]([OH:14])=[O:13])=[CH:2][CH:3]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Under a nitrogen atmosphere, into a reaction vessel were charged 25.17 g (0.233 mol) of 1,4-phenylenediamine and 230 ml of tetrahydrofuran. A solution prepared by dissolving 22.84 g (0.233 mol) of maleic anhydride in 50 ml of tetrahydrofuran was dropped into this under cooling with ice over a period of about 1 hour, then, the mixture was stirred at room temperature overnight. After completion of the reaction, the deposited crystal was isolated by filtration, washed twice with 40 ml of tetrahydrofuran, dried at 40° C. for hours, to obtain 46.92 g of coarse (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoic acid as an orange powder. To 46.92 g of coarse (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoic acid was added 250 ml of methanol, and the mixture was stirred at 50° C. for 1 hour and cooled, then, filtrated and washed twice with 20 ml of methanol. The resultant crystal was dried, to obtain 42.67 g of (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoic acid as a yellow-orange powder. Yield: 88.8%.
Workup
- customA solution prepared
- additionwas dropped into
- temperaturethis under cooling with ice over a period of about 1 hour
- customAfter completion of the reaction
- customthe deposited crystal was isolated by filtration
- washwashed twice with 40 ml of tetrahydrofuran
- customdried at 40° C. for hours
Sources & evidence
- ORD record
- ord-2e259d7577f14f85b7047b903ea8d793
- Source dataset
- uspto-grants-2016_06
- Patent number
- US09365497B2
Reaction notes
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