Water → HCID 178468978、化合物

関与物質

反応手順

A mixture of 4-cyclohexylcyclohexanone (1.54 g), 1-(4-ethoxycarbonylphenyl)piperazine (2 g) and titanium(IV) isopropoxide (3.18 ml) was stirred at room temperature. After 1 hour, the IR spectrum of the mixture showed no ketone band, and the viscous solution was diluted with absolute ethanol (8.5 ml). Sodium cyanoborohydride (0.343 g) was added, and the solution was stirred for 3 hours. Water (3 ml) was added with stirring, and the resulting in organic precipitate was filtered and washed with ethanol. The filtrate was extracted with ethyl acetate. The organic layer was taken and dried over magnesium sulfate. The magnesium sulfate was filtered off, and filtrate was evaporated under reduced pressure. The residue was subjected to column chromatography on silica gel and eluted with (hexane/ethyl acetate)=(3/1). The fractions containing the less polar compound were collected and evaporated under reduced pressure to give ethyl 4-[4-(cis-4-cyclohexylcyclohexyl)piperazin-1-yl]benzoate (692 mg) as byproduct. The fractions containing the more polar compound were collected and evaporated under reduced pressure to give ethyl 4-[4-(trans-4-cyclohexylcyclohexyl)piperazin-1-yl]benzoate (587 mg).

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