Hydrazine hydrate (1:1) → 6-Fluoro-3-(2-fluorobenzyl)-1H-pyrazolo[4,3-b]pyridine

HRID 1528675Notes

Reaction equation

HRID 1528675 reaction equation
F[C:2]1[C:3]([C:9](=O)[CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=2[F:17])=[N:4][CH:5]=[C:6]([F:8])[CH:7]=1.O.[NH2:20][NH2:21]>N1C=CC=CC=1.CN(C)C1C=CN=CC=1.C(OCC)(=O)C>[F:8][C:6]1[CH:7]=[C:2]2[NH:21][N:20]=[C:9]([CH2:10][C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=3[F:17])[C:3]2=[N:4][CH:5]=1

Participants

6

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 666355431-(3,5-Difluoropyridin-2-yl)-2-(2-fluorophenyl)ethanone

Product 1

HCID 1785059746-Fluoro-3-(2-fluorobenzyl)-1H-pyrazolo[4,3-b]pyridine

Reagents, catalysts & solvents 3

HCID 142844-(Dimethylamino)pyridineCatalystHCID 1049PyridineSolventHCID 8857Ethyl AcetateSolvent

Procedure

9.07 g (32.4 mmol) of the compound from example 5A were initially charged in pyridine (84 ml). Subsequently, 8.10 g (162 mmol) of hydrazine hydrate and 19.8 mg (0.162 mmol) of 4-dimethylaminopyridine were added, and the mixture was heated at reflux for 30 min. The reaction mixture was diluted with ethyl acetate at RT and washed four times with 10% strength aqueous citric acid solution. The organic phase was subsequently washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated. MTBE was added to the residue and the solids were filtered off. The latter were dried under high vacuum and gave 1.79 g (79% pure, 18% of theory) of the title compound. The filtrate was concentrated and gave a further 4.86 g (61% pure, 37% of theory) of the title compound. The two fractions were combined and reacted without further purification.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 30 min
  3. washwashed four times with 10% strength aqueous citric acid solution
  4. washThe organic phase was subsequently washed with saturated aqueous sodium chloride solution
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. additionMTBE was added to the residue
  9. filtrationthe solids were filtered off
  10. customThe latter were dried under high vacuum

Sources & evidence

ORD record
ord-6d12efab25834781b1d182988bdd61b3
Source dataset
uspto-grants-2015_07
Patent number
US09090609B2

Reaction notes

Loading…