C5H11N = 85.098.
Piperidine, C5H11N, is prepared by the dry distillation of piperine, the alkaloid of pepper, with soda lime, or synthetically by the reduction of pyridine in alcoholic solution with sodium amalgam, this latter method being a commercial process. It occurs as a colourless, limpid liquid, having an ammoniacal and peppery odour and a burning, caustic taste—bitter when largely diluted—and with a strong alkaline reaction. Specific gravity, 0.876. Boiling point, 106°, at which temperature it distils unchanged. It is a powerful base, and yields crystalline salts with acids. With metallic salts it reacts like ammonium hydroxide, but in the case of zinc and copper it does not redissolve the precipitated hydroxides.
Miscible in all proportions with water and alcohol.
Action and Uses.—Piperidine has a weak coniine-like action, but is rarely used in medicine. The acid tartrate and salicylate are given in gout and rheumatism, in doses of 6 to 10 decigrams (10 to 15 grains), on the assumption that they act as uric acid solvents. The salts are readily soluble in water, and are dispensed in mixture form or in cachets. Piperidine guaiacolate, a compound of piperidine and guaiacol, has been recommended for use in phthisis, in doses of 3 to 20 decigrams (5 to 30 grains). It has a faint odour of guaiacol, is soluble in water, and is decomposed both by acids and alkalies.