Methanol → 5,12-Dihydro-2,9-dimethylquino(2,3-b)acridine-7,14-dione

HRID 2396308Notes

Reaction equation

HRID 2396308 reaction equation
[CH3:1][C:2]1[CH:28]=[CH:27][C:5]([NH:6][C:7]2[CH:15]=[C:14]([C:16]([OH:18])=O)[C:13]([NH:19][C:20]3[CH:25]=[CH:24][C:23]([CH3:26])=[CH:22][CH:21]=3)=[CH:12][C:8]=2[C:9](O)=[O:10])=[CH:4][CH:3]=1.CO>O.[Fe]>[CH3:1][C:2]1[CH:28]=[CH:27][C:5]2[NH:6][C:7]3[C:8]([C:9](=[O:10])[C:4]=2[CH:3]=1)=[CH:12][C:13]1[NH:19][C:20]2[CH:25]=[CH:24][C:23]([CH3:26])=[CH:22][C:21]=2[C:16](=[O:18])[C:14]=1[CH:15]=3

Participants

5

Reactant 2

HCID 887MethanolHCID 825242,5-Di-p-toluidinoterephthalic acid

Product 1

HCID 704235,12-Dihydro-2,9-dimethylquino(2,3-b)acridine-7,14-dione

Reagents, catalysts & solvents 2

HCID 23925IronCatalyst2×HCID 962WaterSolvent2×

Conditions

Temperature
60 °C

Procedure

To 320 g of polyphosphoric acid (111.8% phosphoric acid) heated at 80°-95° C. was added 0.89 g (3.2 mmole) of ferrous sulfate heptahydrate followed by 72 g (0.1915 mole) of essentially iron-free 2,5-di(4-methylanilino)terephthalic acid. The iron content, relative to 2,5-di(4-methylanilino)terephthalic acid, was about 1.7 mole percent. The mixture was heated at 120°-125° C. for two hours. The viscous solution was cooled to 90°-95° C. and then slowly poured into a mixture of 470 g of methanol and 50 g of water at 40° 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, cooled to 60° C., and diluted with 600 g of water. After the slurry was stirred at 60° C. for 30 minutes, the solid component was collected by filtration and washed with water until acid-free. The resultant presscake was reslurried in 800 g of water and 33 g of 50% sodium hydroxide, then heated for 90°-95° C. for two hours. After being cooled to 70° C., the slurry was filtered and washed with water until free of alkali. The resultant presscake was reslurried in 700 g water and heated to 110°-115° C. for two hours in a closed system (e.g., a pressure reactor). After the slurry was cooled to 60°-70° C., the pH was adjusted to 3.5 with phosphoric acid and an emulsion of 2.5 g of sodium dioctyl sulfosuccinate (available as AEROSOL OT from American Cyanamid Co.), 35 g of VM&P Naphtha (available from Unocal Chemicals), and 75 g of water was added. The mixture was stirred at 30°-35° C. for three hours, 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 55 g of 2,9-dimethylquinacridone as a brilliant magenta solid. Based on a rub-out test in linseed oil (as described above), the pigment of Example 5 is significantly bluer in undertone (tint) and deeper in masstone than a comparison pigment that did not contain an iron salt in the ring closure melt or water in the drown solvent.

Workup

  1. temperatureThe mixture was heated at 120°-125° C. for two hours
  2. temperatureThe 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. filtrationthe solid component was collected by filtration
  10. washwashed with water until acid-free
  11. temperature33 g of 50% sodium hydroxide, then heated for 90°-95° C. for two hours
  12. temperatureAfter being cooled to 70° C.
  13. filtrationthe slurry was filtered
  14. washwashed with water until free of alkali
  15. temperatureheated to 110°-115° C. for two hours in a closed system (e.g., a pressure reactor)
  16. temperatureAfter the slurry was cooled to 60°-70° C.
  17. additionan emulsion of 2.5 g of sodium dioctyl sulfosuccinate (available as AEROSOL OT from American Cyanamid Co.), 35 g of VM&P Naphtha (available from Unocal Chemicals), and 75 g of water was added
  18. stirringThe mixture was stirred at 30°-35° C. for three hours
  19. filtrationcollected by filtration
  20. washwashed with water
  21. customdried
  22. customHere, the wet cake was dried in an oven at 60° C.

Sources & evidence

ORD record
ord-2decdb11c7d5491b8e2e5f01f24eb065
Source dataset
uspto-grants-1996_02
Patent number
US05491235

Reaction notes

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