PROCESS FOR THE PREPARATION OF PIPERIDINE

Piperidine is prepared by reacting glutaric acid or its anhydride with ammonia under a pressure of 50-500 bars and a temperature of 150-350 DEG C. in the presence of a hydrogenation catalyst. Preferred catalysts are those comprising ruthenium, rhodium, palladium, platinum, cobalt, nickel, chromium or copper, e.g. ruthenium on carbon black or cobalt on kieselguhr. If desired, a solvent, e.g. water or a cyclic ether, may be present. The piperidine obtained may be purified by washing the catalyst with ethanol and distilling the solution obtained under atmospheric pressure to separate the solvents and piperidine from the non-volatile residue; hydrochloric acid is added to the volatile fraction and the fraction is evaporated to dryness to give piperidine hydrochloride which is treated with caustic soda solution to regenerate the piperidine.