Acetic Acid → Acetic acid--2-(2,2-dicyclohexylethyl)piperidine (1/1)

Participants

Reaction Conditions

Reaction Steps

To a nitrogen-purged ten gallon autoclave is added a slurry of 400 g. of a 5 percent rhodium-on-carbon catalyst (Engelhard Industries) followed by a warm (50° C.) solution of glacial acetic acid and 4.0 kg (15.5 moles) of 2-(2,2-diphenylethenyl)pyridine. The charging system is rinsed using an additional 3.5 liters of glacial acetic acid. The system is purged with nitrogen and then hydrogen gas is introduced to a pressure of 40 atmospheres. The reaction mixture is stirred and heated to a temperature of about 115° C. Hydrogenation is continued at this temperature until no further hydrogen is taken up by the reaction mixture, usually a period of three to four hours. The reaction mixture is cooled to 30°-40° C. and the catalyst removed by filtration. The autoclave is rinsed several times with acetic acid which is then used to wash the catalyst. The combined filtrates are concentrated in vacuo to obtain an oily residue of 2-(2,2-dicyclohexylethyl)piperidine acetate.

Provenance & Evidence