Hydrochloric Acid → cis-1-(3-Chloropropyl)-2,6-dimethylpiperidine

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Reaction Steps

A stirred solution of 171 g. of cis-2,6-dimethyl-1-piperidinepropanol in 400 ml. of benzene is cooled to 0°-5° and 143 g. of thionyl chloride is added dropwise over a period of 30 minutes. The mixture is then heated at reflux for 2 hours, cooled and diluted with 1 l. of ether. The resulting precipitate of cis-1-(3-chloropropyl)-2,6-dimethylpiperidine hydrochloride is collected by filtration; m.p. 173°-174° C. after crystallization from 2-propanol-ether. The free base is prepared as needed by dissolving the hydrochloride in a minimum amount of water, cooling and adding a slight excess of 50% aqueous sodium hydroxide. The liberated base is immediately extracted with several portions of benzene. The extracts are combined, dried and evaporated to give the free base, cis-1-(3-chloropropyl)-2,6-dimethylpiperidine.

Provenance & Evidence