§ 370. Narceine, C23H27NO8 + 3H2O.—Two of the three molecules of water are expelled at 100°, the other molecule requires a higher temperature; anhydrous narceine is hygroscopic, and melts in a tube at about 140°; when exposed to air it unites with one molecule of water, and then melts at about 160°.
The constitution of narceine is probably that of a substituted phenylbenzylketone, and the following structural formula has been attributed to it:[407]—
[407] M. Freund and G. B. Frankforter, Annalen, 277, pp. 20-58.
It therefore contains three methoxyl groups.
Narceine forms good crystals, the form being that of long, four-sided rhombic prisms or fine bushy united needles.
Narceine hydrochloride crystallises with 51⁄2H2O and with 3H2O; the anhydrous salt melts at 190°-192°. The platinochloride is a definite salt, m.p. 190°-191°; it decomposes at 195°-196°. The nitrate forms good crystals, which decompose at 97°. Narceine also forms crystalline salts with potassium and sodium; these may be obtained by heating the base at 60°-70° with a 33 per cent. of NaHO or KHO.