(3-(Trifluoromethyl)phenyl)hydrazine → 4,5-Dibromo-2-[3-(trifluoromethyl)phenyl]pyridazin-3(2H)-one

HRID 1902832Notes

Reaction equation

HRID 1902832 reaction equation
[C:1](O)(=O)/[C:2](=[C:4](\[CH:6]=[O:7])/[Br:5])/[Br:3].[F:10][C:11]([F:21])([F:20])[C:12]1[CH:13]=[C:14]([NH:18][NH2:19])[CH:15]=[CH:16][CH:17]=1>C(O)C>[F:10][C:11]([F:20])([F:21])[C:12]1[CH:13]=[C:14]([N:18]2[C:6](=[O:7])[C:4]([Br:5])=[C:2]([Br:3])[CH:1]=[N:19]2)[CH:15]=[CH:16][CH:17]=1

Participants

4

Reactant 2

HCID 98650(3-(Trifluoromethyl)phenyl)hydrazineHCID 3033972Mucobromic Acid

Product 1

HCID 167793014,5-Dibromo-2-[3-(trifluoromethyl)phenyl]pyridazin-3(2H)-oneYield 68.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 21.4 grams of mucobromic acid and 13.3 grams of 3-trifluoromethylphenyl hydrazine in 60 milliliters of ethanol was stirred for about 10 minutes. The ethanol was removed by evaporation under reduced pressure, and then 40 milliliters each of glacial acetic acid and acetic anhydride were added to the reaction vessel. The acidic reaction mixture was heated at reflux for 4 hours. The reaction solvent was removed by evaporation under reduced pressure whereupon a solid precipitate formed. The solid was purified by recrystallization from ethanol. A yield of 20.7 grams of 1-(3-trifluoromethylphenyl)-4,5-dibromo-1,6-dihydro-6-oxopyridazine was obtained.

Workup

  1. customThe ethanol was removed by evaporation under reduced pressure
  2. addition40 milliliters each of glacial acetic acid and acetic anhydride were added to the reaction vessel
  3. temperatureThe acidic reaction mixture was heated
  4. temperatureat reflux for 4 hours
  5. customThe reaction solvent was removed by evaporation under reduced pressure whereupon a solid precipitate
  6. customformed
  7. customThe solid was purified by recrystallization from ethanol

Sources & evidence

ORD record
ord-4912cb79dc0b4c9dbcf5dc2e40300929
Source dataset
uspto-grants-1982_12
Patent number
US04366155

Reaction notes

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