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

HRID 1417867Notes

Reaction equation

HRID 1417867 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>[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

4

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-dioneYield 97.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
123 °C

Procedure

To 300 g of polyphosphoric acid (112% phosphoric acid) heated at 88° C. was added 68.2 g of 2,5-di(4-methylanilino)terephthalic acid over a period of 35 minutes, the temperature being maintained below 120° C. by adjustment of the addition rate. The reaction mixture was heated at 123° C. for two hours. The melt was cooled to 93° C. and then slowly poured into 526 g of methanol, the temperature being maintained below 64° C. by external cooling and adjustment of melt addition rate. The slurry was heated at reflux for one hour, cooled to below 60° C., diluted with water, collected by filtration, and washed with water until acid free. The resultant presscake was reslurried in water. After adjustment of the pH to greater than 7, 5.5 g of 50% sodium hydroxide was added and the resultant slurry was heated at 90° C. for one hour. The slurry was cooled, filtered, and washed with water until alkaline free, then reslurried in water. After adjustment of the pH to 9.5, the slurry was heated at 143° C. for two hours in a closed system (e.g., a pressure reactor), and cooled to 40° C. After the slurry was acidified to pH 3.3, an emulsion of 2.2 g of an anionic surfactant, 30 g of a petroleum distillate, and 80 g of water was added, and the slurry was stirred for three hours. 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 60 g of 2,9-dimethylquinacridone as a magenta pigment.

Workup

  1. temperaturethe temperature being maintained below 120° C. by adjustment of the addition rate
  2. temperatureThe melt was cooled to 93° C.
  3. temperaturethe temperature being maintained below 64° C.
  4. temperatureby external cooling
  5. additionadjustment of melt addition rate
  6. temperatureThe slurry was heated
  7. temperatureat reflux for one hour
  8. temperaturecooled to below 60° C.
  9. filtrationcollected by filtration
  10. washwashed with water until acid free
  11. additionAfter adjustment of the pH to greater than 7, 5.5 g of 50% sodium hydroxide was added
  12. temperaturethe resultant slurry was heated at 90° C. for one hour
  13. temperatureThe slurry was cooled
  14. filtrationfiltered
  15. washwashed with water until alkaline free,
  16. temperatureAfter adjustment of the pH to 9.5, the slurry was heated at 143° C. for two hours in a closed system (e.g., a pressure reactor)
  17. temperaturecooled to 40° C
  18. additionan emulsion of 2.2 g of an anionic surfactant, 30 g of a petroleum distillate, and 80 g of water was added
  19. customThe wet cake can be dried
  20. customHere, the wet cake was dried in an oven at 60° C.

Sources & evidence

ORD record
ord-4cde85619c1a4407a63a28e9878856d0
Source dataset
uspto-grants-1999_03
Patent number
US05879444

Reaction notes

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