Glyoxal → 8-(4-Fluorophenyl)-7-(pyridin-4-yl)pyrazolo[1,5-b][1,2,4]triazine

HRID 54943

Reaction equation

HRID 54943 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[C:4]([C:7]2[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=2)[C:3]=1[C:13]1[CH:18]=[CH:17][C:16]([F:19])=[CH:15][CH:14]=1.C1(C)C=C(C)C=C(C)C=1S(O[NH2:32])(=O)=O.[CH:34]([CH:36]=O)=O.C(=O)(O)[O-].[Na+]>C(O)C.O>[F:19][C:16]1[CH:17]=[CH:18][C:13]([C:3]2[C:4]([C:7]3[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=3)=[N:5][N:6]3[C:2]=2[N:1]=[CH:36][CH:34]=[N:32]3)=[CH:14][CH:15]=1

Participants

7

Reactant 4

HCID 7860GlyoxalHCID 516892Sodium BicarbonateHCID 11830845O-(2,4,6-Trimethylbenzenesulfonyl)hydroxylamineHCID 178509114HCID 178509114, compound

Product 1

HCID 199572708-(4-Fluorophenyl)-7-(pyridin-4-yl)pyrazolo[1,5-b][1,2,4]triazine

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

To a solution of 5-amino-4-(4-fluorophenyl)-3-(pyridin-4-yl)pyrazole (1.674 g) in ethanol (33 ml) was added O-mesitylsulfonylhydroxylamine (2.362 g). The mixture was stirred at ambient temperature for 30 minutes and to the mixture was added a solution of glyoxal in water (40%, 955 mg). The mixture was refluxed for 4 hours and cooled. The reaction mixture was poured into an aqueous saturated sodium bicarbonate solution and the separated oil was extracted with dichloromethane. The extract was washed with brine, dried and concentrated in vacuo. The residue was purified by column chromatography on silica gel and the obtained oil was crystallized from ethanol to give 8-(4-fluorophenyl)-7-(pyridin-4-yl)pyrazolo[1,5-b][1,2,4]triazine (63 mg).

Workup

  1. temperatureThe mixture was refluxed for 4 hours
  2. temperaturecooled
  3. extractionthe separated oil was extracted with dichloromethane
  4. washThe extract was washed with brine
  5. customdried
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by column chromatography on silica gel
  8. customthe obtained oil was crystallized from ethanol

Sources & evidence

ORD record
ord-6acfb050726d43f8b3a275686f014fbe
Source dataset
uspto-grants-1997_04
Patent number
US05624931

Linked notes

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