Allyl bromide → 4-methyl-1-(prop-2-en-1-yl)-1h-imidazole

HRID 1624336Notes

Reaction equation

HRID 1624336 reaction equation
[CH3:1][C:2]1[N:3]=[CH:4][NH:5][CH:6]=1.[CH2:7](Br)[CH:8]=[CH2:9].C(N(CC)C(C)C)(C)C>CN(C=O)C>[CH2:9]([N:5]1[CH:6]=[C:2]([CH3:1])[N:3]=[CH:4]1)[CH:8]=[CH2:7]

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 81531DiisopropylethylamineHCID 178418800HCID 178418800, compound

Product 1

HCID 2374854-methyl-1-(prop-2-en-1-yl)-1h-imidazoleYield 40%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

4-Methylimidazole (2.0 g, 24.36 mmol), allyl bromide (2.2 mL, 24.36 mmol), N,N-diisopropylethylamine (5.0 mL, 29.24 mmol) in DMF (50 mL) were stirred at 80° C. overnight. Then the reaction mixture was cooled, quenched with saturated NaHCO3 (30 mL), and extracted with CH2Cl2 (4×40 mL). The combined organic layers were dried (MgSO4), filtered, concentrated, and dried in vacuo to afford a brown oil. Purification by flash column chromatography on silica using 2% CH3OH/CH2Cl2 afforded the product as a yellow oil (1.13 g, 40%). 1H NMR (CDCl3) (as a mixture of regio-isomers) δ 2.17 and 2.22 (s, total 3H), 4.44-4.48 (m, total 2H), 5.19-5.24 (m, total 2H), 5.89-6.00 (m, total 1H), 6.61 and 6.79 (s, total 1H), 7.35 and 7.39 (s, total 1H).

Workup

  1. temperatureThen the reaction mixture was cooled
  2. customquenched with saturated NaHCO3 (30 mL)
  3. extractionextracted with CH2Cl2 (4×40 mL)
  4. dry with materialThe combined organic layers were dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customdried in vacuo
  8. customto afford a brown oil
  9. customPurification by flash column chromatography on silica using 2% CH3OH/CH2Cl2

Sources & evidence

ORD record
ord-7e74eee181a34a259c6fd13a62f87e71
Source dataset
uspto-grants-2014_07
Patent number
US08778967B2

Reaction notes

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