3-Iodobenzyl bromide → 3-[(3-iodophenyl)methyl]-2-(1-methylethyl)-3,5,6,7-tetrahydro-4H-benzimidazol-4-one

Participants

Reaction Steps

1-(bromomethyl)-3-iodobenzene (9.76 g) was added to a stirred solution of tetrabutylammonium bromide (4.41 g), Intermediate 56 (2nd alternative preparation) (4.88 g) and 1-(bromomethyl)-3-iodobenzene (9.76 g) in Toluene (100 mL) and NaOH (5M, Aq) (46.5 mL). The reaction mixture was allowed to stir vigorously, so as to ensure mixture of the 2 phases, at room temperature for 2.75 hr. The reaction mixture was partitioned between DCM (80 mL) and water (80 mL) and aqueous layer was washed with further DCM (2×80 mL). The organic layers were combined, filtered through a hydrophobic frit and concentrated in vacuo to give 16.84 g of crude product as a brown oil. The sample was loaded in dichloromethane and purified by column chromatography (silica) using 0-100% ethyl acetate-cyclohexane. The appropriate fractions were combined and evaporated in vacuo to give the required products 5.8 g as a yellow oil which solidified. LC/MS MH+ 394, Rt 2.85 min (5 min run).

Provenance & Evidence