Hydrogen Bromide → 1-(4-Bromo-3-methylphenyl)-1,2,4-triazole

HRID 2392653Notes

Reaction equation

HRID 2392653 reaction equation
[N:1]1([C:6]2[CH:12]=[CH:11][C:9](N)=[C:8]([CH3:13])[CH:7]=2)[CH:5]=[N:4][CH:3]=[N:2]1.N([O-])=O.[Na+].C(N)CN.[BrH:22]>[Cu]Br>[Br:22][C:9]1[CH:11]=[CH:12][C:6]([N:1]2[CH:5]=[N:4][CH:3]=[N:2]2)=[CH:7][C:8]=1[CH3:13]

Participants

6

Reactant 4

HCID 260Hydrogen Bromide2×HCID 3301EthylenediamineHCID 144502622-Methyl-4-[1,2,4]triazol-1-yl-phenylamineHCID 23668193Sodium Nitrite

Product 1

HCID 189801161-(4-Bromo-3-methylphenyl)-1,2,4-triazole

Reagents, catalysts & solvents 1

HCID 24593copper(I) bromideCatalyst

Procedure

4-(1,2,4-Triazol-1-yl)-2-methylaniline (D62, 0.55 g) in 48% HBr (10 ml) at -5° C. was stirred while sodium nitrite (0.3 g) was added portionwise over approximately 5 minutes to give a brown sludge which was left for a further 15 minutes. During this time, copper (1) bromide (0.63 g) was heated under reflux in 48% HBr (2 ml) under argon. The brown sludge was added to it portionwise over 5 minutes and the resulting black reaction mixture heated under reflux for a further 1 minute. After cooling slightly, the mixture was poured gently into 10% aqueous ethylenediamine solution to give a purple solution. Ethyl acetate extraction gave the title compound which was purified by chromatography on silica using 4-10% pentane/ethyl acetate as eluant (0.77 g, 73%) Mass spec (CI) MH+ 238, 240.

Workup

  1. additionwas added portionwise over approximately 5 minutes
  2. customto give a brown sludge which
  3. additionThe brown sludge was added to it portionwise over 5 minutes
  4. temperaturethe resulting black reaction mixture heated
  5. temperatureunder reflux for a further 1 minute
  6. temperatureAfter cooling slightly
  7. customto give a purple solution
  8. extractionEthyl acetate extraction

Sources & evidence

ORD record
ord-1ca5428c2b314895a1b7426d5f0c5789
Source dataset
uspto-grants-1998_09
Patent number
US05801170

Reaction notes

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