Toluene → 9-ethyl-9H-carbazole-3,6-dicarbaldehyde

HRID 1597724Notes

Reaction equation

HRID 1597724 reaction equation
C([C:3]1[C:15]2[NH:14][C:13]3[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=3)[C:7]=2[CH:6]=[CH:5][CH:4]=1)C.CN(C)[CH:18]=[O:19].P(Cl)(Cl)(Cl)=O.[C:26](=[O:29])([O-])[O-].[Na+].[Na+].[C:32]1(C)C=CC=C[CH:33]=1>[Cl-].[Zn+2].[Cl-]>[CH:26]([C:10]1[CH:11]=[CH:12][C:13]2[N:14]([CH2:32][CH3:33])[C:15]3[C:7]([C:8]=2[CH:9]=1)=[CH:6][C:5]([CH:18]=[O:19])=[CH:4][CH:3]=3)=[O:29]

Participants

7

Reactant 5

HCID 1140Toluene2×HCID 6228DimethylformamideHCID 10340Sodium CarbonateHCID 24813Phosphorus oxychlorideHCID 123959591-Ethyl-9H-carbazole

Product 1

HCID 37166759-ethyl-9H-carbazole-3,6-dicarbaldehydeYield 62.9%

Reagents, catalysts & solvents 1

HCID 3007855ZincchlorideCatalyst

Procedure

138.8 g (1.02 mol) of zinc chloride was weighed and put in a 2-liter reaction flask, and 1 liter of toluene was added, followed by dehydration under reflux for 3 hours. The solution was cooled to room temperature, and 100 g (0.51 mol) of ethylcarbazole (4a) (manufactured by Tokyo Kasei Kogyo Co.) and 267.9 g (3.67 mol) of N,N-dimethylformamide were added. Subsequently, 468.3 g (3.05 mol) of phosphorus oxychloride was added elevating the temperature from room temperature to 80° C. over a period of 30 minutes. The flask was heated to 82° C. in an oil bath and stirred for 72 hours. After cooling, the mixture was poured into 5 liters of ice water, and sodium carbonate was slowly added to make the solution basic (pH 10-11). Then, 1 liter of toluene was added, and the resulting solution was stirred at 60° C. for 1 hour. After standing, solution separation was carried out. The toluene phase was washed with water (3 liters×3), dried (MgSO4), and concentrated. The resulting crude crystals (132.1 g) were recrystallized twice from toluene, thus obtaining 79.23 g of 3,6-diformyl-9-ethylcarbazole (2a).

Workup

  1. additionwas added
  2. temperatureunder reflux for 3 hours
  3. customfrom room temperature to 80° C.
  4. customof 30 minutes
  5. temperatureThe flask was heated to 82° C. in an oil bath
  6. temperatureAfter cooling
  7. additionwas slowly added
  8. stirringthe resulting solution was stirred at 60° C. for 1 hour
  9. customsolution separation
  10. washThe toluene phase was washed with water (3 liters×3)
  11. dry with materialdried (MgSO4)
  12. concentrationconcentrated
  13. customThe resulting crude crystals (132.1 g) were recrystallized twice from toluene

Sources & evidence

ORD record
ord-c3b9b48b53b2423793ff1611933a10ee
Source dataset
uspto-grants-1998_04
Patent number
US05736284

Reaction notes

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