1,1-Dibromoethane → 1-Trityl-4-(4-cyanobenzyl)imidazole

HRID 363182Notes

Reaction equation

HRID 363182 reaction equation
BrC(Br)C.[CH:5]1[C:10]([CH2:11]Br)=[CH:9][CH:8]=[C:7]([C:13]#[N:14])[CH:6]=1.I[C:16]1[N:17]=[CH:18][N:19]([C:21]([C:34]2[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=2)([C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)[C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)[CH:20]=1>C1COCC1.[Zn]>[C:21]([N:19]1[CH:20]=[C:16]([CH2:11][C:10]2[CH:9]=[CH:8][C:7]([C:13]#[N:14])=[CH:6][CH:5]=2)[N:17]=[CH:18]1)([C:28]1[CH:29]=[CH:30][CH:31]=[CH:32][CH:33]=1)([C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

6

Reactant 3

HCID 112011,1-DibromoethaneHCID 869964-(Bromomethyl)benzonitrileHCID 6182524-Iodo-1-tritylimidazole

Product 1

HCID 158375331-Trityl-4-(4-cyanobenzyl)imidazole

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
20 °C

Procedure

To a suspension of activated zinc dust (3.57 g, 54.98 mmol) in THF (50 mL) was added dibromoethane (0.315 mL, 3.60 mmol) and the reaction stirred under argon at 20° C. The suspension was cooled to 0° C. and a-bromo-p-tolunitrile (9.33 g, 47.6 mmol) in THF (100 mL) was added dropwise over a period of 10 minutes. The reaction was then allowed to stir at 20° C. for 6 hours and bis(triphenylphosphine)Nickel II chloride (2.4 g, 3.64 mmol) and 4-iodo-1-tritylimidazole (15.95 g, 36.6 mmol, S. V. Ley, et al., J. Org. Chem. 56, 5739 (1991)) were added in one portion. The resulting mixture was stirred 16 hours at 20° C. and then quenched by addition of sat. aq. NH4Cl solution (100 mL) and the mixture stirred for 2 hours. Saturated aq. NaHCO3 solution was added to give a pH of 8 and the solution was extracted with EtOAc (2×250 mL), dried, (MgSO4) and the solvent evaporated in vacuo. The residue was chromatographed (Silica gel, 0-20% EtOAc in CH2Cl2 to afford the title compound as a white solid.

Workup

  1. temperatureThe suspension was cooled to 0° C.
  2. stirringto stir at 20° C. for 6 hours
  3. stirringThe resulting mixture was stirred 16 hours at 20° C.
  4. customquenched by addition of sat. aq. NH4Cl solution (100 mL)
  5. stirringthe mixture stirred for 2 hours
  6. additionSaturated aq. NaHCO3 solution was added
  7. customto give a pH of 8
  8. extractionthe solution was extracted with EtOAc (2×250 mL)
  9. customdried
  10. custom(MgSO4) and the solvent evaporated in vacuo
  11. customThe residue was chromatographed (Silica gel, 0-20% EtOAc in CH2Cl2

Sources & evidence

ORD record
ord-a785ba13d8df4fd8ac4230542d2f41f4
Source dataset
uspto-grants-1999_02
Patent number
US05872136

Reaction notes

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