Phenylhydrazine → 9-Bromo-1,5-dimethyl-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indol-4-one

HRID 1384818Notes

Reaction equation

HRID 1384818 reaction equation
[C:1]([C:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][C:11]=2[Br:13])[N:6]([CH3:14])[C:5]=1[C:15]([O:17]C)=O)(=O)[CH3:2].[C:19]1([NH:25][NH2:26])[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>C(O)(=O)C>[Br:13][C:11]1[C:12]2[C:4]3[C:1]([CH3:2])=[N:26][N:25]([C:19]4[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=4)[C:15](=[O:17])[C:5]=3[N:6]([CH3:14])[C:7]=2[CH:8]=[CH:9][CH:10]=1

Participants

4

Reactant 2

HCID 7516Phenylhydrazine2×HCID 21183733Methyl 3-acetyl-4-bromo-1-methyl-1H-indole-2-carboxylate

Product 1

HCID 211837429-Bromo-1,5-dimethyl-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indol-4-oneYield 42.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

22 g (71 mmol) of methyl 3-acetyl-4-bromo-1-methyl-1H-indole-2-carboxylate are dissolved with heating in 350 ml of acetic acid. 30 ml (300 mmol) of phenylhydrazine are added, stirring is carried out for 1 h at room temperature and the reaction mixture is heated at reflux for 5 h, at room temperature for 15 h and then again at reflux for 7 h. 28 ml of phenylhydrazine are added and the process is repeated. The mixture is concentrated under reduced pressure, the residue is taken up in water and the precipitate is collected by filtration, washed with water and dried under reduced pressure. It is purified by chromatography on a column of silica gel. 11.1 g (30 mmol) of product are isolated.

Workup

  1. temperaturethe reaction mixture is heated
  2. temperatureagain at reflux for 7 h
  3. concentrationThe mixture is concentrated under reduced pressure
  4. filtrationthe precipitate is collected by filtration
  5. washwashed with water
  6. customdried under reduced pressure
  7. customIt is purified by chromatography on a column of silica gel

Sources & evidence

ORD record
ord-e8b78df8108e475daa4c11da7614d2c0
Source dataset
uspto-grants-2001_07
Patent number
US06262045B1

Reaction notes

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