Potassium Iodide → 1-(4-fluorophenyl)-5-iodo-1H-indazole

HRID 218163Notes

Reaction equation

HRID 218163 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]3[C:11](=[CH:12][C:13](N)=[CH:14][CH:15]=3)[CH:10]=[N:9]2)=[CH:4][CH:3]=1.N([O-])=O.[Na+].[I-:22].[K+]>Cl.O>[F:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]3[C:11](=[CH:12][C:13]([I:22])=[CH:14][CH:15]=3)[CH:10]=[N:9]2)=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 4875Potassium IodideHCID 23668193Sodium NitriteHCID 592357271-(4-Fluorophenyl)-1h-indazol-5-amine

Product 1

HCID 592511281-(4-fluorophenyl)-5-iodo-1H-indazoleYield 39%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent2×

Conditions

Temperature
0 °C

Procedure

To N1-(4-fluorophenyl)-5-aminoindazole (25.6 g, 113 mmol) suspended in 500 mL 6 M HCl and cooled to 0° C. was added a solution of sodium nitrite (8.2 g, 119 mmol) dissolved in 75 mL water, portionwise. After 3 h, potassium iodide (22.5 g, 136 mmol) dissolved in 80 mL water was added and the reaction was stirred overnight. The next day, the reaction was transferred to a beaker and carefully quenched by adding solid sodium carbonate. After neutralization and addition of water, the aqueous phase was extracted 4× EtOAc. The combined organic extracts were dried over MgSO4, filtered, concentrated, and filtered from hot EtOAc. The filtrate was concentrated and purified on a 330 g SiO2 MPLC column using DCM. Obtained 13.2 g of 1-(4-fluorophenyl)-5-iodo-1H-indazole (39%). MS found: (M+H)+=339.

Workup

  1. additionwas added
  2. customcarefully quenched
  3. additionby adding solid sodium carbonate
  4. additionAfter neutralization and addition of water
  5. extractionthe aqueous phase was extracted 4× EtOAc
  6. dry with materialThe combined organic extracts were dried over MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. filtrationfiltered from hot EtOAc
  10. concentrationThe filtrate was concentrated
  11. custompurified on a 330 g SiO2 MPLC column

Sources & evidence

ORD record
ord-bf465c077b22405491efa19f677b1de7
Source dataset
uspto-grants-2012_06
Patent number
US08198311B2

Reaction notes

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