Bromide ion → N,N,N',N'-Tetramethylbenzidine

HRID 268509

Reaction equation

HRID 268509 reaction equation
[CH3:1][N:2]([CH3:11])[C:3]1[CH:8]=[CH:7][C:6]([Mg]Br)=[CH:5][CH:4]=1.[Br-]>>[CH3:1][N:2]([CH3:11])[C:3]1[CH:8]=[CH:7][C:6]([C:6]2[CH:7]=[CH:8][C:3]([N:2]([CH3:11])[CH3:1])=[CH:4][CH:5]=2)=[CH:5][CH:4]=1

Participants

3

Reactant 2

HCID 259Bromide ionHCID 178482849HCID 178482849, compound

Product 1

HCID 9702N,N,N',N'-TetramethylbenzidineYield 70%

Procedure

A mixture of p-dimethylaminophenyl magnesium bromide (1 mole) and thallous bromide (2 moles) is stirred and refluxed under nitrogen for 5 hours. The cooled solution is filtered to remove thallium, and hydrogen chloride passed into the filtrate. The colorless hydrochloride which precipitates is filtered off, stirred into dilute sodium hydroxide, and the tetramethylbenzidine extracted with ether-benzene (1:1, 2 × 30 ml.) The extracts are dried over anhydrous sodium sulfate and the solvent removed to leave a yellow solid which is sublimed at 165°/0.05 mm. to give a 70% yield of pure N,N,N',N'-tetramethylbenzidine as a colorless solid, m.p. 195°.

Workup

  1. temperaturerefluxed under nitrogen for 5 hours
  2. filtrationThe cooled solution is filtered
  3. customto remove thallium, and hydrogen chloride
  4. customThe colorless hydrochloride which precipitates
  5. filtrationis filtered off
  6. extractionthe tetramethylbenzidine extracted with ether-benzene (1:1, 2 × 30 ml.) The extracts
  7. dry with materialare dried over anhydrous sodium sulfate
  8. customthe solvent removed
  9. customto leave a yellow solid which
  10. customis sublimed at 165°

Sources & evidence

ORD record
ord-145b57532358474db24c4671adfe7f3a
Source dataset
uspto-grants-1976_03
Patent number
US03947488

Linked notes

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