Sodium Hydroxide → 3,3',5,5'-Tetramethylbenzidine

HRID 2397603Notes

Reaction equation

HRID 2397603 reaction equation
Br[C:2]1[CH:8]=[C:7]([CH3:9])[C:5]([NH2:6])=[C:4]([CH3:10])[CH:3]=1.[OH-].[Na+].C([O-])=O.[Na+]>[Pd].[Br-].C([N+](C)(C)C)CCCCCCCCCCCCCCC.O>[CH3:10][C:4]1[CH:3]=[C:2]([C:2]2[CH:8]=[C:7]([CH3:9])[C:5]([NH2:6])=[C:4]([CH3:10])[CH:3]=2)[CH:8]=[C:7]([CH3:9])[C:5]=1[NH2:6]

Participants

7

Reactant 3

HCID 14798Sodium HydroxideHCID 905494-Bromo-2,6-xylidineHCID 2723810Sodium Formate3×

Product 1

HCID 412063,3',5,5'-TetramethylbenzidineYield 63.3%

Reagents, catalysts & solvents 3

HCID 5974Hexadecyltrimethylammonium BromideCatalystHCID 23938PalladiumCatalystHCID 962WaterSolvent

Procedure

4-Bromo-2,6-dimethylaniline (24.0 parts), 3% palladium on charcoal (50% paste; 2.0 parts), cetyltrimethylammonium bromide (4.0 parts), sodium hydroxide liquor (32%; 13.5 parts), sodium formate (6.8 parts) in water (60 parts) are stirred at the boil under reflux for 3 hours. Sodium formate (6.8 parts is then added and the mixture boiled for 3 hours when a further charge of sodium formate (6.8 parts) is made. The reaction mixture is then held at the boil under reflux for a further 23 hours. The mixture is then steam distilled and from the distillate 2.2 parts (18.2%) of 2,6-dimethylaniline is recovered by extraction with ether. The reaction mixture after steam distillation is cooled to room temperature and then filtered. The residue is extracted continuously with methanol (60 parts) for 5 hours and then the extract cooled. The colourless crystalline precipitate is filtered off and dried to give 7.7 parts (63.3%) of 3,3',5,5'-tetramethyl benzidine.

Workup

  1. temperatureunder reflux for 3 hours
  2. temperatureunder reflux for a further 23 hours
  3. distillationsteam distilled and from the distillate 2.2 parts (18.2%) of 2,6-dimethylaniline
  4. customis recovered by extraction with ether
  5. distillationThe reaction mixture after steam distillation
  6. filtrationfiltered
  7. extractionThe residue is extracted continuously with methanol (60 parts) for 5 hours
  8. temperaturethe extract cooled
  9. filtrationThe colourless crystalline precipitate is filtered off
  10. customdried

Sources & evidence

ORD record
ord-e442844c76fd4e4d833b347290a3306d
Source dataset
uspto-grants-1977_05
Patent number
US04022795

Reaction notes

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