Hydrazinecarboxylic acid, ethyl ester → 6-(p-Bromophenyl)-2-ethyl-7-methyl-1,2,4-triazolo[4,3-b]pyridazin-3(2H)-one

HRID 462411Notes

Reaction equation

HRID 462411 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[N:9]=[N:10][C:11](Cl)=[CH:12][C:13]=2[CH3:14])=[CH:4][CH:3]=1.C(OCC)(=O)NN.BrC1C=CC(C2C(C)=[CH:32][C:33]3[N:34]([C:36](=[O:39])NN=3)[N:35]=2)=CC=1>C(O)CCC>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:13]([CH3:14])=[CH:12][C:11]3[N:10]([C:36](=[O:39])[N:34]([CH2:33][CH3:32])[N:35]=3)[N:9]=2)=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 20064Hydrazinecarboxylic acid, ethyl esterHCID 203982886-(p-bromophenyl)-7-methyl-1,2,4-triazolo[4,3-b]pyridazin-3(2H)-oneHCID 203982893-(p-Bromophenyl)-6-chloro-4-methylpyridazine

Product 1

HCID 134246016-(p-Bromophenyl)-2-ethyl-7-methyl-1,2,4-triazolo[4,3-b]pyridazin-3(2H)-one

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent

Procedure

A mixture comprising 328 g. of 3-(p-bromophenyl)-6-chloro-4-methylpyridazine (U.S. Pat. No. 4,092,311), 242 g. of ethyl carbazate and 2 liters of butanol is stirred at reflux for 4 days, then cooled in an ice bath. The resulting solid is collected by filtration and air dried, giving 269 g. of 6-(p-bromophenyl)-7-methyl-1,2,4-triazolo[4,3-b]pyridazin-3(2H)-one.

Workup

  1. temperatureat reflux for 4 days
  2. temperaturecooled in an ice bath
  3. filtrationThe resulting solid is collected by filtration and air
  4. customdried
  5. customgiving 269 g

Sources & evidence

ORD record
ord-d6682ab3a24e4b729f4473a4e4706efd
Source dataset
uspto-grants-1985_05
Patent number
US04515791

Reaction notes

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