Hydrazine hydrate (1:1) → 3-(3-Oxo-2,3,4,5-tetrahydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine

HRID 466013Notes

Reaction equation

HRID 466013 reaction equation
O=[C:2]([C:8]1[C:9]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)=[N:10][N:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=12)[CH2:3][CH2:4][C:5](O)=[O:6].O.[NH2:24][NH2:25]>C(O)C>[O:6]=[C:5]1[CH2:4][CH2:3][C:2]([C:8]2[C:9]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)=[N:10][N:11]3[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=23)=[N:25][NH:24]1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 151581654-Oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)butyric acid

Product 1

HCID 151581133-(3-Oxo-2,3,4,5-tetrahydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridineYield 70.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 4-oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)butyric acid (1.71 g), hydrazine monohydrate (1.46 g) and ethanol (17 ml) was heated under reflux for 1 hour. Ethanol was evaporated in vacuo. Water (20 ml) was added to the residue, acidified with 5% hydrochloric acid and extracted with chloroform (25 ml×3). The combined extract was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and evaporated in vacuo. The residue was recrystallized from ethanol to give crystals of 3-(3-oxo-2,3,4,5-tetrahydropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (1.19 g).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 1 hour
  3. customEthanol was evaporated in vacuo
  4. additionWater (20 ml) was added to the residue
  5. extractionextracted with chloroform (25 ml×3)
  6. extractionThe combined extract
  7. washwas washed with a saturated aqueous solution of sodium chloride
  8. dry with materialdried over magnesium sulfate
  9. customevaporated in vacuo
  10. customThe residue was recrystallized from ethanol

Sources & evidence

ORD record
ord-e7d81c263bcf49ed88d9af1ef7c934af
Source dataset
uspto-grants-1992_10
Patent number
US05155114

Reaction notes

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