Imidazole → 2-(1-Imidazolyl)-3-methylindole

HRID 1903409Notes

Reaction equation

HRID 1903409 reaction equation
[CH3:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[NH:4][CH:3]=1.[NH:11]1[CH:15]=[CH:14][N:13]=[CH:12]1.BrBr>O1CCOCC1.Cl>[N:11]1([C:3]2[NH:4][C:5]3[C:10]([C:2]=2[CH3:1])=[CH:9][CH:8]=[CH:7][CH:6]=3)[CH:15]=[CH:14][N:13]=[CH:12]1

Participants

6

Reactant 3

HCID 795ImidazoleHCID 6736SkatoleHCID 24408Bromine

Product 1

HCID 132808392-(1-Imidazolyl)-3-methylindole

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 312751,4-DioxaneSolvent2×

Procedure

To a solution of 3-methylindole (7.87 g) and imidazole (20.42 g) in dioxane (350 ml) stirring at 10° is added a solution of bromine (3.1 ml) in dioxane (125 ml) dropwise over a period of 25 hrs. Upon complete addition, the cooling bath is removed and the resulting yellow suspension is allowed to warm to room temperature while stirring overnight. The solid which had formed is removed by vacuum filtration. The filtrate is concentrated in vacuo to give an amber oil. This oil is suspended in 2 N HCl (100 ml) and washed with ether (3×100 ml). The acidic layer is made basic to pH 10 with 3 N NaOH and extracted with ether (6×100 ml). The ether extract is dried (MgSO4), filtered and concentrated in vacuo to give a partially crystalline residue. This residue is triturated with petroleum ether/ether and the solid which resulted is collected and recrystallized from acetonitrile (30 ml) to give 2-(1-imidazolyl)-3-methylindole, m.p. 156°-158°.

Workup

  1. additionUpon complete addition
  2. customthe cooling bath is removed
  3. customThe solid which had formed
  4. customis removed by vacuum filtration
  5. concentrationThe filtrate is concentrated in vacuo
  6. customto give an amber oil
  7. washwashed with ether (3×100 ml)
  8. extractionextracted with ether (6×100 ml)
  9. extractionThe ether extract
  10. dry with materialis dried (MgSO4)
  11. filtrationfiltered
  12. concentrationconcentrated in vacuo
  13. customto give a partially crystalline residue
  14. customThis residue is triturated with petroleum ether/ether
  15. customthe solid which resulted
  16. customis collected
  17. customrecrystallized from acetonitrile (30 ml)

Sources & evidence

ORD record
ord-13b2f585b6b148d6a85daaab3d1bb840
Source dataset
uspto-grants-1984_03
Patent number
US04436746

Reaction notes

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