1-(1-Methyl-2-piperidinyl)acetone

This alkaloid occurs in the bark of Punica Granatum L. and was first isolated by Piccinini under the name of isomethylpelletierine. The base is an oily liquid with an alkaline reaction, miscible with H20 and optically inactive. The hydrochloride has m.p. lS6°C; the hydrobromide, m.p. lSI-2°C; the aurichloride forms rosettes of orange-yellow needles, m.p. lIS-7°C and the picrate has m.p. lS7-8°C. The alkaloid may be resolved into its optically active components. (+)-methy1isopelletierine (+)-hydrogen tartrate has m.p. 133-4°C; [α]²⁰_D + 22.7°, the corresponding figures for the antipode being m.p. 132-40c;~aH)S - 20.83° while the two hydrochlorides have [α]¹⁸_D + 11.08° and - 10.64° respectively.
The base gives a semicarbazone as colourless crystals, m.p. 169°C; an oxime, b.p. 1600C/12 mm and a hydrazone, b.p. lS4-SoC/29 mm. The methiodide yields cubic crystals, m.p. lS6°C. Oxidation with chromic acid in H2S04 furnishes N-methylpiperidine-2-carboxylic acid.

Piccinini., Gazzetta, 29, ii, 311 (1899)
Hess et al., Ber., SO, 344, 1386 (1917)
Hess et al., ibid, 51,741 (1918)
Hess et al., ibid, 52, 964, 100S (1919)