4-Nitrophthalic acid anhydride → 4-Aminophthalic anhydride

HRID 66396

Reaction equation

[N+:1]([C:4]1[CH:5]=[C:6]2[C:11](=[O:12])[O:10][C:8](=[O:9])[C:7]2=[CH:13][CH:14]=1)([O-])=O.[H][H]>C(OCC)C.[Pd]>[NH2:1][C:4]1[CH:5]=[C:6]2[C:11](=[O:12])[O:10][C:8](=[O:9])[C:7]2=[CH:13][CH:14]=1

Participants

Conditions

Temperature: 245 °C

Procedure

In 200 ml of dry ethyl ether, (C2H5)2O, was dissolved 1.93 g of 4-nitrophthalic anhydride (~ 1% solution) to which was added 0.10 g of 5% palladium-on-charcoal and the mixture hydrogenated in a Paar hydrogenator at 39 psi at room temperature, until no more hydrogen was consumed. The catalyst was removed by filtration and the ether removed from the filtrate, maintained at 0° to -5° C, under vacuo, yielding a yellow crystalline solid mixed with non-crystalline viscous mass. When a small sample of this mixture was placed on a metal plate heated to 245° C, the product melted and polymerized immediately to a tough polymer. Extraction of the crystalline-non-crystalline mixture with ether left 0.46 g of polymer; concentration of the ether followed by cooling, yielded 0.86 g of 4-aminophthalic anhydride.

Workup

customwas consumed
customThe catalyst was removed by filtration
customthe ether removed from the filtrate
temperaturemaintained at 0° to -5° C, under vacuo
customyielding a yellow crystalline solid
additionmixed with non-crystalline viscous mass
custompolymerized immediately to a tough polymer
extractionExtraction of the crystalline-non-crystalline mixture with ether
waitleft 0.46 g of polymer
temperatureby cooling

Sources & evidence

ORD record: ord-38965d72a83f4820b52f1ccaccc9bcdb
Source dataset: uspto-grants-1978_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04131730

Linked notes

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