Acetic Acid → 1-Carbamoyl-3-(4-fluorophenacyl)piperidine

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Reaction Steps

1-Cyano-3-(4-fluorophenacyl)piperidine (Example 19), 21.5 g, was dissolved in a mixture of 150 ml of glacial acetic acid, 30 ml of concentrated aqueous hydrochloric acid, and 70 ml of water. The resulting solution, under a nitrogen atmosphere, was heated on a steam-bath for 16 hours. The reaction solution was distilled under reduced pressure, the residue was diluted with water, and the resulting solution was made alkaline with 3 N sodium hydroxide. Upon extracting the alkaline aqueous solution with ethyl ether, solid precipitated and was isolated by filtration and washed with ether. The solid, 6.7 g, was recrystallized once from aqueous acetone and then four times from acetone/diethyl ether, to give 1-carbamoyl-3-(4-fluorophenacyl)piperidine, mp 136°-137.5°. The following elemental analysis was obtained:

Provenance & Evidence