The constitution of cytisine, the alkaloid of Cytisus laburnum. Pt. 1. The synthesis of [alpha]-cytisolidine and of [beta]-cytisolidine / by Arthur James Ewins.
- Ewins, Arthur James.
- Date:
- 1913
Licence: In copyright
Credit: The constitution of cytisine, the alkaloid of Cytisus laburnum. Pt. 1. The synthesis of [alpha]-cytisolidine and of [beta]-cytisolidine / by Arthur James Ewins. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
8/14 (page 100)
![dimethyltetrakydroquinolines was commenced in collaboration with Mr. H. King, and some of the results of this work are described in the succeeding paper (Ewins and King, p. 104). The work carried out in this direction unexpectedly threw a further light on the relationship of a-cytisolidine to /3-cytisolidine, the basic oil obtained by the action of hydriodic acid on cytisine. The last-mentioned authors found a well-marked and fairly constant difference in the properties of the dimethyltetrahydroquinolines and the corresponding dimethylquinolines, chiefly in the melting points and solubilities of their salts. A similar relationship was observed to exist between the a- and /3-cytisolidines, and a closer examination and analysis showed that the latter possessed the composition CnHnN, and not CnH]5N, as stated by Freund (loc. cit.). It was therefore very probable that a-cytisolidine was the dimethyltetra- hydroquinoline corresponding with the dimethylquinoline, /3-cytiso- lidine, a relationship which was readily confirmed, /3-cytisolidine on reduction with sodium in alcoholic solution giving a base identical with a-cytisolidine. The problem thus resolved itself into the identification of /3-cytisolidine as (probably) a dimethylquinoline. Here, again, there are twenty-one possible isomerides, of which about a dozen have been described, but again for the most part very imperfectly. Finally, after a number of these dimethylquinolines had been prepared, the synthesis of 6 :8-dimethylquinoline from m-4-xylidine was carried out. The base so obtained proved to be identical with /3-cytisolidine, and on reduction yielded another base identical with a-cytisolidine. The constitution of these two bases is thus estab- lished beyond doubt. Further, cytisoline must be a corresponding kydroxydimetliylquinoline. This is confirmed by the fact that on distillation with zinc dust /3-cytisolidine is obtained. The position of the hydroxy-grou2J is, however, as yet undetermined; but it is most probably either in the 3- or 4-position, since 2-hydroxy-6:8- dimetliylquinoline prepared by the action of hypochlorous acid on 6:8-dimethylquinoline, although agreeing closely in general proper- ties with cytisoline, was found to be different. 5-Hydroxy-6:8-di- methylquinoline was also synthesised, but the properties of this substance differ considerably from cytisoline, owing to the phenolic character of the hydroxy-group, for which reason also 7-kydroxy- 6:8-dimethylquinoline may most probably be eliminated. Experi- ments to determine the constitution of cytisoline are in progress. The constitution of cytisine itself still remains an open question. It is to be noticed, however, that cytisoline, CnHnON, which, from the results recorded in this communication, must be a hydroxydi- methylquinoline, is formed from cytisine by the loss of the elements](https://iiif.wellcomecollection.org/image/b22439146_0008.jp2/full/800%2C/0/default.jpg)
