Sodium Hydroxide → HCID 86708819, compound

Temperature

5 °C

Under a nitrogen atmosphere, into a reaction vessel were charged 195.5 g (1.81 mol) of 1,4-phenylenediamine and 3000 ml of tetrahydrofuran. A solution prepared by dissolving 118.1 g (1.20 mol) of maleic anhydride in 1200 ml of tetrahydrofuran was dropped into this under cooling with ice over a period of about 3 hours, then, the mixture was stirred at room temperature overnight. After completion of the reaction, the deposited crystal was isolated by filtration, washed twice with 250 ml of tetrahydrofuran, and dried at 40° C. to obtain 241.8 g of coarse (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoic acid as a yellow-orange powder. To 241.8 g of coarse (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoic acid was added 484 ml of water, and the mixture was cooled to 0 to 10° C., and 216 ml of a 5N sodium hydroxide aqueous solution was dropped, then, 21 ml of a 1N sodium hydroxide aqueous solution was dropped. Thereafter, the solvent was distilled off under reduced pressure to obtain a residue to which 200 ml of 2-propanol was added, and the solvent was distilled off under reduced pressure again. To the resultant yellow-brown solid was added 800 ml of tetrahydrofuran, the mixture was stirred at room temperature overnight, and the solid was isolated by filtration, washed three times with 100 ml of tetrahydrofuran and dried, to obtain 279 g of coarse sodium (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoate. Coarse sodium (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoate (279 g) was bisected, 2800 ml of methanol was added to each portion, refluxed with heating for 1 hour, then, hot-filtrated to remove insoluble materials. The filtrates were condensed under reduced pressure, and the resultant solids were combined, 750 ml of tetrahydrofuran was added and the mixture was stirred at room temperature overnight, thermally insulated at 50° C. for 30 minutes, then, hot-filtrated. The resultant solid was washed three times with 150 ml of tetrahydrofuran, dried under reduced pressure at 45° C. for 5 hours, to obtain 264.6 g of sodium (2Z)-4-[(4-aminophenyl)amino]-4-oxo-2-butenoate methanol solvate as a pale brown-white powder. Yield: 84.5%.

1. distillationThereafter, the solvent was distilled off under reduced pressure
2. customto obtain a residue to which 200 ml of 2-propanol
3. additionwas added
4. distillationthe solvent was distilled off under reduced pressure again
5. additionTo the resultant yellow-brown solid was added 800 ml of tetrahydrofuran
6. customthe solid was isolated by filtration
7. washwashed three times with 100 ml of tetrahydrofuran
8. customdried

ORD record

ord-387b307f07f54f74b4df21b79f9a4ff5

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09068055B2