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

HRID 463803

Reaction equation

HRID 463803 reaction equation
P(=O)(O)(O)O.[C:6]1([CH3:33])[CH:11]=[CH:10][C:9]([NH:12][C:13]2[CH:21]=[C:20]([C:22]([OH:24])=O)[C:19]([NH:25][C:26]3[CH:31]=[CH:30][C:29]([CH3:32])=[CH:28][CH:27]=3)=[CH:18][C:14]=2[C:15](O)=[O:16])=[CH:8][CH:7]=1>O>[CH3:32][C:29]1[CH:28]=[CH:27][C:26]2[NH:25][C:19]3[C:20]([C:22](=[O:24])[C:31]=2[CH:30]=1)=[CH:21][C:13]1[NH:12][C:9]2[CH:8]=[CH:7][C:6]([CH3:33])=[CH:11][C:10]=2[C:15](=[O:16])[C:14]=1[CH:18]=3

Participants

4

Reactant 2

HCID 1004Phosphoric AcidHCID 825242,5-Di-p-toluidinoterephthalic acid2×

Product 1

HCID 704235,12-Dihydro-2,9-dimethylquino(2,3-b)acridine-7,14-dioneYield 15%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
40 °C

Procedure

Two hundred ml of polyphosphoric acid and 100 ml of 85% phosphoric acid are mixed in a mechanically stirred beaker and allowed to cool to 40° C. Thirty grams of 2,5-di(p-tolylamino)terephthalic acid (DTTA) are added in small portions, successively, under intense agitation by Gifford-Wood homogenizer. Care is taken to dissolve each portion before adding another one. The temperature is kept below 60° C. by external water bath cooling. After having dissolved all of the DTTA, as ascertained by dipping a glass rod into the viscous reaction medium and examining for solid particles clinging to the rod, the solution is transferred into a 500 ml round-bottom flask equipped with mechanical stirrer, CaSO4 drying tube, N2 inlet and thermometer, and heated to 100° C. within 45 minutes with stirring. The temperature is held at 100° C. for 45 minutes. The solution develops an orange-brown fluorescense during this time. The solution is poured into 2 l of water with mechanical stirring, generating a dark-colored precipitate. Stirring is continued for 10 minutes. The precipitate is filtered, washed acid-free with water and suspended in 2 l of H2O. The suspension is made basic with a pH of 12 by adding 50 wt % aqueous NaOH solution with stirring, is heated, kept at 60° C. for 15 minutes with continued stirring and filtered while warm. The filter cake is washed with water and dried in a vacuum oven at 70°-80° C. to give 4.0 g (15% yield) of apparently 2,9-dimethylquinacridone by-product. The filtrate and wash water combined are acidified with acetic acid to a pH of 4, with stirring. The resulting red precipitate is filtered, washed acid-free with water and dried overnight at 70°-80° C. under vacuum and slight N2 purge to give 22.3 g (78% yield) of red 2-(p-tolyl)amino-3-carboxy-7-methyl-9(10H)acridinone (TMCA).

Workup

  1. dissolutionto dissolve each portion
  2. additionbefore adding another one
  3. customThe temperature is kept below 60° C. by external water bath
  4. temperaturecooling
  5. customthe solution is transferred into a 500 ml round-bottom flask
  6. customequipped with mechanical stirrer, CaSO4 drying tube, N2 inlet
  7. temperaturethermometer, and heated to 100° C. within 45 minutes
  8. stirringStirring
  9. waitis continued for 10 minutes
  10. filtrationThe precipitate is filtered
  11. washwashed acid-free with water
  12. additionby adding 50 wt % aqueous NaOH solution
  13. stirringwith stirring
  14. temperatureis heated
  15. waitkept at 60° C. for 15 minutes
  16. stirringwith continued stirring
  17. filtrationfiltered
  18. temperaturewhile warm
  19. washThe filter cake is washed with water
  20. customdried in a vacuum oven at 70°-80° C.

Sources & evidence

ORD record
ord-004a1934ce8543d9a2b77b0122e07605
Source dataset
uspto-grants-1985_10
Patent number
US04544746

Linked notes

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