Licence: In copyright
Credit: The plant alkaloids / by Thomas Anderson Henry. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![sation of the Z-hydrogen tartrates. More recently Ladenburg has stated that synthetic d-coniine so obtained has a higher rotation than the natural alkaloid, probably due to the presence of iso- coniine {see above), but that the rotation can be reduced to that of the natural alkaloid by long-continued heating at 290°.^ iV-Methyl-d-COniine, CgHjeN.CHa. This alkaloid is stated to occur in hemlock in minute quantities. ^ According to Wolffenstein it remains with y-coniceine, when the latter is separated from coniine by the fractional crystallisation of the acid tartrates, von Braun separates the tertiary bases (methylconiines) from crude coniine by benzoylating the latter, dissolving the product in ether, and extracting the tertiary bases with dilute acid.^ It has been obtained synthetically by heating coniine with potassium methyl sulphate.^ It is a colourless oily coniine-like liquid, b.p. 173°-174°, D2V3 0-8318 and -j- 81'33°. The ordinary salts are crystal- line ; the hydrochloride, B.HCl, forms masses of needles, m.p. 188° ; the platinichloride, Bg-HaPtClg, has m.p. 158°. A-Methyl-Z-COniine was obtained by Ahrens ® from residues left in the preparation of coniine by crystallisation of the hydrobromides, that of d-coniine being much less soluble in water, or by converting coniine into the nitroso-compound. It is a colourless, coniine-like liquid, b.p. 175-6°/767 mm., D“ 0-8349, [a]p“ — 81-92°. The hydrochloride, B.HCl, forms needles, m.p. 191°-192°, the hydrobromide, B.HBr, crystallises in leaflets, m.p. 189°-190°, the platinichloride in orange crystals, m.p. 153°-154°, and the anrichloride in brilliant leaflets, m.p. 77°-78°. The relationship of von Braun’s methylconiine ® to the foregoing has not yet been settled. A series of alkylconiines has been prepared and described by Scholtz.'^ Conhydrine, CgHi^ON. This oxygenated alkaloid was first found in hemlock by Wertheim.® In the extraction of coniine from 1 BericJde, 1906, 39, 2486. ^ Planta and Kekul6, Annalen, 1854, 89, 1.50. ® Berichte, 1905, 38, 3108. * Passon, Berichte, 1891, 24, 1678, ® Berichte, 1902, 35, 1330. ® Loc. cif. ’ Berichte, 1904, 37, 3627 ; 1905, 38, 595. ® Annalen, 1856, iOO, 1329,](https://iiif.wellcomecollection.org/image/b2196189x_0041.jp2/full/800%2C/0/default.jpg)
