Imidazole → 1-[(Benzyloxy)methyl]4,5-dibromo-2-ethylimidazole

HRID 650264Notes

Reaction equation

HRID 650264 reaction equation
[Br:1][C:2]1[N:3]=[C:4]([CH2:8][CH3:9])[NH:5][C:6]=1[Br:7].C([O-])([O-])=O.[K+].[K+].Cl[CH2:17][O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.N1C=CN=C1>CN(C=O)C.CCOC(C)=O.CCCCCC>[CH2:19]([O:18][CH2:17][N:3]1[C:2]([Br:1])=[C:6]([Br:7])[N:5]=[C:4]1[CH2:8][CH3:9])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

7

Reactant 4

HCID 795ImidazoleHCID 11430Potassium CarbonateHCID 137983Benzyl chloromethyl etherHCID 104674684,5-dibromo-2-ethyl-1H-imidazole

Product 1

HCID 186690441-[(Benzyloxy)methyl]4,5-dibromo-2-ethylimidazoleYield 85%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 21226206Ethyl acetate hexaneSolvent

Procedure

To a mechanically stirred solution of 4,5-dibromo-2-ethylimidazole (25.4 g, 0.1 mole,) in anhydrous DMF (250 mL) was treated with K2CO3 (69.1 g, fw=138.2, 0.5 moles, 5 equiv.) followed by dropwise addition of benzyl chloromethyl ether (18.5 g, 0.11 moles, 93% pure, TCI, fw=156.61) and stirred overnight at room temp under nitrogen for 20 h. TLC (30:70 EtOAc/hexane) revealed absence of starting material imidazole (Rf=0.2) along with formation of product (Rf=0.71). The reaction mixture was filtered, washed the solid with dichloromethane and the combined filterate was evaporated under reduced pressure and purified the crude (47 g) by flash column chromatography (dichloromethane eluent) to afford 31.75 g (85%) of colorless oil. Mass spectrum (m/z=375, M+H).

Workup

  1. filtrationThe reaction mixture was filtered
  2. washwashed the solid with dichloromethane
  3. customthe combined filterate was evaporated under reduced pressure
  4. custompurified the crude (47 g) by flash column chromatography (dichloromethane eluent)

Sources & evidence

ORD record
ord-ef47792ab6354f6093dc279e8d99998b
Source dataset
uspto-grants-2001_08
Patent number
US06271380B1

Reaction notes

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