Triphenylphosphine → (Z)-2-[3-(2,5,7-trimethyl-3H-imidazo[4,5-b]pyridin-3-yl)methyl-6,11-dihydrodibenzo[b,e]oxepin-11-ylidene]propiononitrile

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Reaction Steps

[step 1] (Z)-2-(3-Hydroxymethyl-6,11-dihydrodibenzo[b,e]oxepin-11-ylidene)propiononitrile (400 mg, 1.44 mmol) obtained in Reference Example B6 and 2,5,7-trimethyl-3H-imidazo[4,5-b]pyridine (U.S. Pat. No. 5,332,744; 349 mg, 2.16 mmol) were dissolved in THF (14 mL), polymer-supported triphenylphosphine (962 mg, 2.88 mmol) and di-tert-butyl azodicarboxylate (664 mg, 2.88 mmol) were added at 0° C., and the mixture was stirred at room temperature for 2 hr. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=4/6) to give (Z)-2-[3-(2,5,7-trimethyl-3H-imidazo[4,5-b]pyridin-3-yl)methyl-6,11-dihydrodibenzo[b,e]oxepin-11-ylidene]propiononitrile (310 mg, 51%).

Provenance & Evidence