Ethanol hydrochloride → 7-[(3S)-3-(Dimethylamino)pyrrolidinyl]-5-methyl-6-phenyl-2-(2-phenylethyl)-1,3-benzoxazole-4-carbonitrile

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7-[(3S)-3-(Dimethylamino)pyrrolidin-1-yl]-5-methyl-6-phenyl-2-[(E)-2-phenylethenyl]-1,3-benzoxazole-4-carbonitrile (I-93) (100 mg, 0.22 mmol) and 1 N hydrochloric acid/ethanol solution (223 μl, 10.22 mmol) were dissolved in ethanol (2 ml), 10% carbon-held palladium catalyst was added, followed by stirring at room temperature under atmospheric pressure of hydrogen for 3 hours. After filtration through Celite, the solvent was concentrated under reduced pressure, ethyl acetate and an aqueous saturated sodium hydrogencarbonate solution were added to make the aqueous layer basic, followed by fractionation. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate. The solvent was evaporated away, the resulting residue was subjected to preparative thin-layer silica gel column chromatography, eluted with a mixed solvent of chloroform/methanol (20:1, v/v), recrystallized and purified with n-hexane/ethyl acetate/diisopropyl ether to obtain the entitled compound (16 mg, 16%) as a white solid.

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