Dimethyl Sulfoxide → 5-bromo-1-(4-fluorophenyl)-1H-indazole

HRID 244422Notes

Reaction equation

HRID 244422 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](F)=[C:6](/[CH:8]=[N:9]/[NH:10][C:11]2[CH:16]=[CH:15][C:14]([F:17])=[CH:13][CH:12]=2)[CH:7]=1.C(=O)([O-])[O-].[Cs+].[Cs+].CS(C)=O>O>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[N:10]([C:11]1[CH:16]=[CH:15][C:14]([F:17])=[CH:13][CH:12]=1)[N:9]=[CH:8]2

Participants

5

Reactant 3

HCID 679Dimethyl SulfoxideHCID 10796Cesium carbonateHCID 9784662N-[(E)-(5-bromo-2-fluorophenyl)methylideneamino]-4-fluoroaniline

Product 1

HCID 468307945-bromo-1-(4-fluorophenyl)-1H-indazoleYield 99.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
220 °C

Procedure

A 30 mL microwave vial was charged with 3.00 g (9.642 mmol) of N-[1-(5-bromo-2-fluorophenyl)meth-(E)-ylidene]-N′-(4-fluorophenyl)hydrazine and 3.14 g (9.64 mmol) of cesium carbonate and 10 mL of DMSO and sealed. The mixture was warmed at 220° C. in the microwave for 15 minutes cooled and opened at room temperature. The mixture was diluted with 10 mL of water and extracted with 20 mL of EtOAc. The organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo. The residue was absorbed onto silica gel and passed through a silica pad and eluted with 50% EtOAc-hexanes. The partially purified material from the pad was triturated with MeOH, collected by filtration, and dried to afford 2.8 g (99.7%) of 5-bromo-1-(4-fluorophenyl)-1H-indazole. MS m/z 279.11 (MH+).

Workup

  1. customsealed
  2. temperaturecooled
  3. customopened at room temperature
  4. extractionextracted with 20 mL of EtOAc
  5. washThe organic layer was washed with brine
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customThe residue was absorbed onto silica gel
  10. washeluted with 50% EtOAc-hexanes
  11. customThe partially purified material from the pad was triturated with MeOH
  12. filtrationcollected by filtration
  13. customdried

Sources & evidence

ORD record
ord-7ad0092ea0cf4c50a94a6c726ba15fd5
Source dataset
uspto-grants-2014_02
Patent number
US08658637B2

Reaction notes

Loading…