Imidazo(1,2-a)pyridine → 3-Iodoimidazo[1,2-a]pyridine

HRID 246237Notes

Reaction equation

HRID 246237 reaction equation
[N:1]1[CH:2]=[CH:3][N:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=12.C([Li])CCC.[I:15]N1C(=O)CCC1=O>C1COCC1.O.CCCCCC.C1COCC1.C(Cl)Cl>[I:15][C:3]1[N:4]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]2=[N:1][CH:2]=1

Participants

8

Reactant 3

HCID 78960Imidazo(1,2-a)pyridineHCID 120273N-IodosuccinimideHCID 178418339Butyllithium

Product 1

HCID 107527743-Iodoimidazo[1,2-a]pyridine

Reagents, catalysts & solvents 4

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 21919333Tetrahydrofurane dichloromethaneSolvent

Procedure

In a 1 L three-necked flask, imidazo[1,2-a]pyridine (4.1 g, 34.7 mmol), in THF was treated with butyllithium (14.6 ml, 36.4 mmol) at −50° C. N-iodosuccinimide (8.59 g, 38.2 mmol) in 50 ml THF and added slowly and temp allowed to rise to 0° C. This was diluted with water and hexane. The organic layer was washed with 10% brine/water (2×), dried (MgSO4) and evaporated to give a solid. The solid was dissolved in THF/DCM and purified by flash chromatography (80-100% ethyl acetate/hexane) to give the desired isomer 3-iodoimidazo[1,2-a]pyridine. 1H NMR (300 MHz, DMSO-d6) δ: 8.32 (m, 1H) 7.72 (s, 1H) 7.62 (m, 1H) 7.34 (m, 1H) 7.06 (t, 1H).

Workup

  1. customto rise to 0° C
  2. washThe organic layer was washed with 10% brine/water (2×)
  3. dry with materialdried (MgSO4)
  4. customevaporated
  5. customto give a solid
  6. custompurified by flash chromatography (80-100% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-328612db09a148ef9c00332b3cbbacd9
Source dataset
uspto-grants-2014_02
Patent number
US08658646B2

Reaction notes

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