Pyridine → HCID 13710341, compound

HRID 364217Notes

Reaction equation

HRID 364217 reaction equation
[CH3:1][N:2]([CH3:18])[C:3]1[CH:4]=[C:5]2[C:14](=[CH:15][CH:16]=1)[N:13]=[C:12]1[C:7](=[CH:8][C:9](=[O:17])[CH:10]=[CH:11]1)[S:6]2.[C:19](OC(=O)C)(=[O:21])[CH3:20].N1C=CC=CC=1.[C:32](OCC)(=[O:34])[CH3:33]>[Zn]>[CH3:1][N:2]([CH3:18])[C:3]1[CH:4]=[C:5]2[C:14](=[CH:15][CH:16]=1)[N:13]([C:19](=[O:21])[CH3:20])[C:12]1[CH:11]=[CH:10][C:9]([O:17][C:32](=[O:34])[CH3:33])=[CH:8][C:7]=1[S:6]2

Participants

6

Reactant 4

HCID 1049PyridineHCID 7918Acetic AnhydrideHCID 8857Ethyl Acetate2×HCID 730243H-Phenothiazin-3-one, 7-(dimethylamino)-2×

Product 1

HCID 13710341HCID 13710341, compound

Reagents, catalysts & solvents 1

HCID 23994ZincCatalyst

Procedure

Under a nitrogen atmosphere, a mixture of 5.0 g of 7-dimethylaminophenothiazin-3-one (commercially known as methylene violet), 75.0 ml of acetic anhydride, 5.0 ml of pyridine and 5.0 g of zinc dust was maintained at reflux temperature for approximately three hours. After cooling to room temperature, the reaction mixture was filtered to remove the insolubles and the filter cake was washed twice, each time with 50.0 ml of acetone. The combined filtrate and acetone washes was poured slowly into water and toluene was added to the resulting mixture. After stirring for approximately thirty minutes, the layers were separated and the water layer was discarded. The organic extract was treated with activated charcoal, filtered and the toluene was removed by evaporation at reduced pressure to obtain a gummy residue. The residue was dissolved with ethyl acetate and the resulting solution was passed through a chromatography column packed with silica gel using ethyl acetate to elute the column. The first four fractions were combined, concentrated, and the solid which formed was collected by filtration and dried to obtain 2.6 g of 7-dimethylamino-3-acetyloxy- 10-acetylphenothiazine (Formula I: R=R1 =R3 =CH), a white powder which melted at 124° to 128° C. The mass spectrum showed significant maxima at 342 (M+) and 299 (M+ --CH3CO). Paper coated with an ink formulation containing the product produced a blue-gray-colored image when contacted with an applied voltage stylus.

Workup

  1. temperaturewas maintained
  2. temperatureat reflux temperature for approximately three hours
  3. filtrationthe reaction mixture was filtered
  4. customto remove the insolubles
  5. washthe filter cake was washed twice
  6. additionThe combined filtrate and acetone washes was poured slowly into water and toluene
  7. additionwas added to the resulting mixture
  8. customthe layers were separated
  9. extractionThe organic extract
  10. additionwas treated with activated charcoal
  11. filtrationfiltered
  12. customthe toluene was removed by evaporation at reduced pressure
  13. customto obtain a gummy residue
  14. washto elute the column
  15. concentrationconcentrated
  16. customthe solid which formed
  17. filtrationwas collected by filtration
  18. customdried

Sources & evidence

ORD record
ord-9ee942e8804a4352a908d102c0f0e8f1
Source dataset
uspto-grants-1986_08
Patent number
US04604458

Reaction notes

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