Methanol → Quinacridone

HRID 1291941Notes

Reaction equation

HRID 1291941 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.P(=O)(O)(O)O.CO>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

5

Reactant 3

HCID 887MethanolHCID 1004Phosphoric AcidHCID 823512,5-Dianilinoterephthalic acid

Product 1

HCID 13976QuinacridoneYield 90%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
123 °C

Procedure

To 270 g of polyphosphoric acid (117% phosphoric acid) heated at 80° C. was added 60 g of 2,5-dianilinoterephthalic acid. The reaction mixture was heated at 123° C. for four hours. After the melt was cooled to 94° C., the acid strength was adjusted to 110% by the dropwise addition of phosphoric acid. The melt was stirred for 20 minutes and then slowly poured into 400 g of methanol, the temperature being maintained below 60° C. by external cooling and adjustment of melt addition rate. The slurry was heated at reflux for one hour and diluted with water, after which the solid component was collected by filtration and washed with water until acid free. The resultant presscake was reslurried in water. After adjustment of the pH to about 7, 6 g of 50% sodium hydroxide was added and the resultant slurry was heated at 90° C. for two hours. The slurry was cooled, filtered, and washed with water until alkaline free, then reslurried in water. After adjustment of the pH to 9.3, 3.2 g of a cycloaliphatic carboxylic acid was added. The resultant slurry was heated at 142° C. for two hours in a closed system, cooled, acidified with phosphoric acid, and stirred. The solid component was collected by filtration and washed with water. The wet cake can be dried or used as is for specific applications. Here, the wet cake was dried in an oven at 60° C. to give approximately 48.4 g of quinacridone as a violet pigment.

Workup

  1. temperatureAfter the melt was cooled to 94° C.
  2. temperaturethe temperature being maintained below 60° C.
  3. temperatureby external cooling
  4. additionadjustment of melt addition rate
  5. temperatureThe slurry was heated
  6. temperatureat reflux for one hour
  7. filtrationafter which the solid component was collected by filtration
  8. washwashed with water until acid free
  9. additionAfter adjustment of the pH to about 7, 6 g of 50% sodium hydroxide was added
  10. temperaturethe resultant slurry was heated at 90° C. for two hours
  11. temperatureThe slurry was cooled
  12. filtrationfiltered
  13. washwashed with water until alkaline free,
  14. additionAfter adjustment of the pH to 9.3, 3.2 g of a cycloaliphatic carboxylic acid was added
  15. temperatureThe resultant slurry was heated at 142° C. for two hours in a closed system
  16. temperaturecooled
  17. stirringstirred
  18. filtrationThe solid component was collected by filtration
  19. washwashed with water
  20. customThe wet cake can be dried
  21. customHere, the wet cake was dried in an oven at 60° C.

Sources & evidence

ORD record
ord-85f83dada62a47a29991e8918dd40184
Source dataset
uspto-grants-1998_05
Patent number
US05755873

Reaction notes

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