[4-(Methoxycarbonyl)benzyl](triphenyl)phosphonium bromide → 4-{(E)-3-cyclohexyl-3-[2-(2,6-dimethoxy-pyridin-3-yl)-5,6-difluoro-benzoimidazol-1-yl]-propenyl}-benzoic acid methyl ester

Participants

Reaction Steps

To a solution of 296 mg (0.60 mmol) 4-carbomethoxybenzyl triphenylphosphonium bromide in 5 ml tetrahydrofuran was added 68 mg (0.602 mmol) potassium tert-butoxide at 0° C. and the reaction mixture was stirred for 15 min. Then, 250 mg (0.60 mmol) cyclohexyl-[2-(2,6-dimethoxy-pyridin-3-yl)-5,6-difluoro-benzoimidazol-1-yl]-acetaldehyde was added at 0° C. The cooling bath was removed and the reaction mixture was stirred for 4 hours at room temperature. The reaction was poured on 30 ml 10% aqueous citric acid and 30 ml ethyl acetate and the layers were separated. The aqueous layer was extracted a second time with 30 ml ethyl acetate. The combined organic layers were washed with 30 ml brine, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue was purified by silica chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) eluting with a gradient of n-heptane:ethyl acetate (100:0 to 70:30). Colorless solid (67%). MS (TurboSpray): m/z=547.2 [M+H].

Provenance & Evidence