Hydrogen Bromide → 2-(4-Bromophenyl)-2H-tetrazole

HRID 2392676Notes

Reaction equation

HRID 2392676 reaction equation
[N:1]1[N:2]([C:6]2[CH:12]=[CH:11][C:9](N)=[CH:8][CH:7]=2)[N:3]=[N:4][CH:5]=1.N([O-])=O.[Na+].C(N)CN.[BrH:21]>[Cu]Br>[N:1]1[N:2]([C:6]2[CH:12]=[CH:11][C:9]([Br:21])=[CH:8][CH:7]=2)[N:3]=[N:4][CH:5]=1

Participants

6

Reactant 4

HCID 260Hydrogen Bromide2×HCID 3301EthylenediamineHCID 5716394-(2H-1,2,3,4-tetrazol-2-yl)anilineHCID 23668193Sodium Nitrite

Product 1

HCID 5608042-(4-Bromophenyl)-2H-tetrazoleYield 38%

Reagents, catalysts & solvents 1

HCID 24593copper(I) bromideCatalyst

Procedure

4-(Tetrazol-2-yl)aniline (450 mg, 2.8 mmol) in 48% HBr (10 ml) at -5° C. was stiired while sodium nitrite (193 mg, 2.8 mmol) was added portionwise over 5 minutes. The brown sludge was left stirring for 15 minutes and then added portionwise over 5 minutes to a refluxing mixture of copper (I) bromide (401 mg, 2.8 mmol) in 48% HBr (2 ml). The mixture was then heated at reflux for 1 minute, allowed to cool slightly, and poured into 10% ethylene diamine solution (20 ml). The aqueous solution was extracted with ethyl acetate, dried (Na2SO4), and evaporated to dryness under reduced pressure. The resulting mixture was purified by column chromatography on silica eluting with n-pentanelethyl acetate (4-10%) to afford the title compound as a white solid (238 mg, 38%).

Workup

  1. customat -5° C.
  2. additionwas added portionwise over 5 minutes
  3. waitThe brown sludge was left
  4. temperatureThe mixture was then heated
  5. temperatureat reflux for 1 minute
  6. temperatureto cool slightly
  7. extractionThe aqueous solution was extracted with ethyl acetate
  8. dry with materialdried (Na2SO4)
  9. customevaporated to dryness under reduced pressure
  10. customThe resulting mixture was purified by column chromatography on silica eluting with n-pentanelethyl acetate (4-10%)

Sources & evidence

ORD record
ord-a5879a2b4826495cb884d4beea6238bd
Source dataset
uspto-grants-1998_09
Patent number
US05801170

Reaction notes

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