Water → N-butylpiperidine-4-carboxamide

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Reaction Steps

Isonicotinoyl chloride (100.0 g) was added over 1 hour to a solution of n-butylamine (51.6 g) in toluene (600 ml) at 0°. The mixture was allowed to stand overnight, heated on a steam bath for 1/2 hour, then water was added. The aqueous layer was separated, basified to about pH 12 (NaOH), and extracted with ethyl acetate (2 times). The combined organic extracts were dried (MgSO4), evaporated and the resulting residue (36.0 g) dissolved in acetic acid (400 ml) and hydrogenated at 50 p.s.i./30° in the presence of platinum oxide. The catalyst was removed by filtration, the solution evaporated to dryness, the residue basified to about pH 12 (Na2CO3), and extracted with chloroform. The chloroform extracts were dried (Na2SO4) and evaporated to give 4-(N-n-butylcarbamoyl)piperidine, (18.7 g), m.p. 75°-79°. The oxalate salt was prepared in isopropanol from the free base and oxalic acid and was recrystallised from isopropanol/ethyl acetate, m.p. 143°-144° .

Provenance & Evidence