P-Phenylenediamine → (2Z)-4-[(4-Aminophenyl)amino]-4-oxo-2-butenoic acid

Participants

Reaction Steps

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%.

Provenance & Evidence