2,5-Dianilinoterephthalic acid → Quinacridone

HRID 845562Notes

Reaction equation

HRID 845562 reaction equation
[NH:1]([C:8]1[CH:16]=[C:15]([C:17](O)=[O:18])[C:14]([NH:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)=[CH:13][C:9]=1[C:10](O)=[O:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1>O>[CH:24]1[CH:25]=[C:26]2[C:17]([C:15]3[C:14]([NH:20][C:21]2=[CH:22][CH:23]=1)=[CH:13][C:9]1[C:10]([C:7]2[C:2]([NH:1][C:8]=1[CH:16]=3)=[CH:3][CH:4]=[CH:5][CH:6]=2)=[O:11])=[O:18]

Participants

3

Reactant 1

HCID 823512,5-Dianilinoterephthalic acid

Product 1

HCID 13976QuinacridoneYield 96%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

50 parts of 2,5-dianilinoterephthalic acid are added with stirring at 125° C. to 225 parts of acid methyl polyphosphate (P2O5 content about 83%) in the course of 1 hour, and the mixture is stirred at said temperature for 2 hours. The cyclization melt is hydrolyzed by means of 300 parts of ice and 375 parts of water. The quinacridone formed is filtered off and is washed with water until neutral. The water-moist approximately 22% strength quinacridone is suspended in 400 parts of water. 18 parts of a 5% strength aqueous cetyltrimethylammonium chloride solution are added dropwise with stirring in the course of 10 minutes. After 30 minutes of stirring 75 parts of 10% strength potassium hydroxide solution are added, and the suspension is bulked to 750 parts with water. The suspension, possibly after a wet milling, is then stirred at 100° C. for 10 hours. It is then filtered and the filter cake is washed with water until neutral. The isolated water-moist approximately 18-22% strength quinacridone is suspended in 300 parts of 80% strength isobutanol, and the suspension is stirred at 145° C. in a sealed vessel for 5 hours. The isobutanol is separated off by steam distillation, and the bluish red pigment is isolated by filtration. The pigment obtained after drying in a yield of above 96% of theory produces when used in paint systems high-hiding, non-hazy, brilliant full-tone coatings of excellent gloss. The gloss value measured as described in Example 1 is 59.5.

Workup

  1. customfor 2 hours

Sources & evidence

ORD record
ord-577e9f4a983942308491375024746dfa
Source dataset
uspto-grants-1988_07
Patent number
US04758665

Reaction notes

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