Water → 6-[2-[4-[2-(2-Fluorophenyl)acetyl]piperidino]ethyl]-1H-pyrazin-2-one

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Reaction Steps

After dissolving 1.00 g of 2-(2-fluorophenyl)-1-(piperidin-4-yl)ethanone hydrochloride in 8 ml of N,N-dimethylformamide, 643 mg of potassium carbonate and 899 mg of 2-tert-butoxy-6-vinylpyrazine were added while stirring, and the stirring was continued for 64 hours at 100° C. Water was added to the reaction mixture and extraction was performed with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was purified by NH silica gel column chromatography (solvent: n-hexane/ethyl acetate). Three milliliters of 4N hydrogen chloride/ethyl acetate was added to the obtained product and the mixture was stirred for 2.5 hours at room temperature. A 1N sodium hydroxide solution was added to the reaction solution and extraction was performed with dichloromethane. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (solvent: chloroform/methanol/ammonia water) to obtain the title compound (27 mg, 2% yield).

Provenance & Evidence