Cesium carbonate → [5-(2-{3-Cyano-4-[3-(3-methylphenyl)propoxy]phenyl}ethynyl)-2,2-dimethyl-1,3-dioxan-5-yl]carbamic acid t-butyl ester

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Reaction Steps

Compound 208-1 (1.04 g), (5-ethynyl-2,2-dimethyl-1,3-dioxan-5-yl)carbamic acid t-butyl ester (0.885 g), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (0.093 g), bis(acetonitrile)palladium(II) dichloride (0.017 g), cesium carbonate (2.67 g) were stirred in acetonitrile (30 ml) at 90° C. for 7 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate, washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography to give [5-(2-{3-cyano-4-[3-(3-methylphenyl)propoxy]phenyl}ethynyl)-2,2-dimethyl-1,3-dioxan-5-yl]carbamic acid t-butyl ester as a pale-brown solid. The solid was dissolved in ethyl acetate (10 ml), 10% palladium carbon (containing about 50% water, 0.140 g) was added and the mixture was stirred under a hydrogen atmosphere at room temperature for 3 hr. The solution was filtered, and the filtrate was concentrated to give the object product (0.360 g) as a yellow oil.

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