Hydrogen Bromide → HCID 20343985, compound

Participants

Reaction Steps

A mixture of 4-cyano-1-methyl-4-(2-phenylthiophenyl)-piperidine, free base of Example 3, in 15 ml of 48% hydrobromic acid is stirred at reflux for 16 hours. Thereafter, the excess acid is removed under reduced pressure, leaving a solid to which is added 10 ml of freshly distilled thionyl chloride. A clear solution results as the mixture is warmed on a steam bath. The excess thionyl chloride is distilled off, leaving a residue which is dissolved in 50 ml of absolute ethyl alcohol. The alcoholic solution is stirred at reflux for 1 hour and then permitted to stand for 16 hours. Then, the ethyl alcohol and any excess acid is removed under reduced pressure. The residue is dissolved in water and the aqueous solution is basified with dilute, ice cold sodium bicarbonate, liberating an amine which is dissolved in ether. The ethereal solution is dried before concentrating in vacuo. The residue, in ether, is converted to its hydrobromic acid salt which is recrystallized from a methyl alcohol-acetone-ether mixture to give 4-ethylcarbonyl-1-methyl-4-(2-phenylthiophenyl)piperidine hydrobromide.

Provenance & Evidence