Methanol → Quinacridone

HRID 2396306Notes

Reaction equation

HRID 2396306 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.[Fe]>[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

6

Reactant 3

HCID 887MethanolHCID 1004Phosphoric AcidHCID 823512,5-Dianilinoterephthalic acid2×

Product 1

HCID 13976QuinacridoneYield 94.2%

Reagents, catalysts & solvents 2

HCID 23925IronCatalyst2×HCID 962WaterSolvent

Conditions

Temperature
85 °C

Procedure

To 270 g of polyphosphoric acid (117.4% phosphoric acid) heated at 80°-95° C. was added 0.75 g (2.7 mmole) of ferrous sulfate heptahydrate followed by 60 g (0.17 mole) of 2,5-dianilinoterephthalic acid containing about 583 ppm (about 0.63 mmole) of iron. The total iron content, relative to 2,5-dianilinoterephthalic acid, was about 1.9 mole percent. The mixture was heated at 120°-125° C. for four hours. After the viscous solution was cooled to 90°-95° C., the acid strength was adjusted to 107% by the dropwise addition of 75% phosphoric acid (65 g). The resultant melt was stirred for 20 minutes and then slowly poured into 400 g of methanol at 35° C. The temperature of the resultant slurry was allowed to rise during the addition to about 64° C., with the temperature being controlled during addition by external cooling and adjustment of melt addition rate. The slurry was heated at reflux (68°-72° C.) for one hour and diluted with 600 g of water. After the slurry was stirred for 30 minutes, the solid component was collected by filtration and washed with water until acid-free. The resultant presscake was reslurried in 1000 g of water and 5 g of 50% sodium hydroxide, then heated for 85° C. for two hours. After being cooled to 60° C., the slurry was filtered and washed with water until free of alkali. After the presscake was reslurried in 800 g water, a solution containing 37 g of water, 1.6 g of 50% sodium hydroxide, and 3.15 g of naphthenic acid was added. The resultant slurry was heated to 140°-145° C. for two hours in a closed system (e.g., a pressure reactor). After cooling the slurry to 60°-70° C., the pH was adjusted to 4.5-5.0 with phosphoric acid, stirred for one hour, collected by filtration, and washed with water. The wet cake can be oven dried or used as is for specific applications. Here, the wet cake was dried in an oven at 60° C. to give about 50 g of quinacridone as a brilliant violet solid.

Workup

  1. temperatureThe mixture was heated at 120°-125° C. for four hours
  2. temperatureAfter the viscous solution was cooled to 90°-95° C.
  3. additionto rise during the addition to about 64° C., with the temperature
  4. additionbeing controlled during addition
  5. temperatureby external cooling
  6. additionadjustment of melt addition rate
  7. temperatureThe slurry was heated
  8. temperatureat reflux (68°-72° C.) for one hour
  9. stirringAfter the slurry was stirred for 30 minutes
  10. filtrationthe solid component was collected by filtration
  11. washwashed with water until acid-free
  12. temperatureAfter being cooled to 60° C.
  13. filtrationthe slurry was filtered
  14. washwashed with water until free of alkali
  15. additiona solution containing 37 g of water, 1.6 g of 50% sodium hydroxide, and 3.15 g of naphthenic acid
  16. additionwas added
  17. temperatureThe resultant slurry was heated to 140°-145° C. for two hours in a closed system (e.g., a pressure reactor)
  18. temperatureAfter cooling the slurry to 60°-70° C.
  19. stirringstirred for one hour
  20. filtrationcollected by filtration
  21. washwashed with water
  22. customdried
  23. customHere, the wet cake was dried in an oven at 60° C.

Sources & evidence

ORD record
ord-3b188b6162bd4fe7a689fc001c0bfb31
Source dataset
uspto-grants-1996_02
Patent number
US05491235

Reaction notes

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