Potassium Carbonate → (E)-{2-[1-(2-propyl-4-methylbenzimidazol-1-yl)ethyl]-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene}acetonitrile

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Reaction Steps

[step 1] (E)-[2-(1-Hydroxyethyl)-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene]acetonitrile (67 mg, 0.24 mmol) obtained in Example 83, step 2 was dissolved in dichloromethane (1 mL), boron tribromide (1.0 mol/L dichloromethane solution; 0.73 mL, 0.73 mmol) was added at 0° C., and the mixture was stirred for 20 min. Water was added to the mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was dissolved in DMA (0.5 mL), 2-propyl-4-methylbenzimidazole (63 mg, 0.36 mmol) and potassium carbonate (100 mg, 0.72 mmol) were added, and the mixture was stirred at 70° C. for 4 hr. Water was added to the mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=50/50) to give (E)-{2-[1-(2-propyl-4-methylbenzimidazol-1-yl)ethyl]-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ylidene}acetonitrile (46 mg, 45%).

Provenance & Evidence