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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence