Iodine → 7-ethyl-3-iodo-1H-indazole

HRID 246541Notes

Reaction equation

HRID 246541 reaction equation
C(=O)(O)[O-].[Na+].[CH2:6]([C:8]1[CH:9]=[CH:10][CH:11]=[C:12]2[C:16]=1[NH:15][N:14]=[CH:13]2)[CH3:7].[I:17]I>O.C(O)C>[CH2:6]([C:8]1[CH:9]=[CH:10][CH:11]=[C:12]2[C:16]=1[NH:15][N:14]=[C:13]2[I:17])[CH3:7]

Participants

6

Reactant 3

HCID 807IodineHCID 516892Sodium BicarbonateHCID 126391947-ethyl-1H-indazole

Product 1

HCID 1784358267-ethyl-3-iodo-1H-indazoleYield 48.2%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

To a stirred solution of sodium bicarbonate (1.67 g, 19.8 mmol) in water (4.65 mL) and ethanol (9.3 mL) was added 7-ethyl-1H-indazole (771 mg, 5.27 mmol) followed by iodine (1.87 g, 7.38 mmol). After 16 h the reaction mixture was quenched with sodium thiosulfate, diluted with ethyl acetate and washed with water. The organic layer was collected and dried (MgSO4). Purification by chromatography (silica, 5-25% ethyl acetate/hexanes) gave 7-ethyl-3-iodo-1H-indazole (690 mg, 2.54 mmol, 48%) as an off-white solid. MS (M+H)+=272.9; 1H NMR (CDCl3) δ: 7.39 (d, J=8.1 Hz, 1H), 7.30 (d, J=7.1 Hz, 1H), 7.22 (t, J=7.1 Hz, 1H), 2.95 (q, J=7.5 Hz, 2H), 1.41 (t, J=7.5 Hz, 3H).

Workup

  1. customAfter 16 h the reaction mixture was quenched with sodium thiosulfate
  2. additiondiluted with ethyl acetate
  3. washwashed with water
  4. customThe organic layer was collected
  5. dry with materialdried (MgSO4)
  6. customPurification by chromatography (silica, 5-25% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-21cb82bd52a04ab6a3e58e34e3d36d4a
Source dataset
uspto-grants-2014_02
Patent number
US08658646B2

Reaction notes

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