Chemical examination of scammony root and of scammony / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1912?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of scammony root and of scammony / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

    10/20 (page 405)
    contained 0‘3536 gram of the resin, gave — 1°2V in a l-dcm. tube, whence —19*1°. Hydrolysis of the Ethereal Extract with Barium Hydroxide. A quantity (500 grams) of the dry ethereal extract of the resin was dissolved in alcohol, and, after the addition of a little water, a cold saturated solution of barium hydroxide was gradually added until the liquid showed an alkaline reaction. It was then kept at a temperature of 35—45°, and the alkalinity maintained by the further occasional addition of small portions of solution of barium hydroxide. This treatment was continued until the liquid gave no turbidity when mixed with water, after which the alcohol was removed by distillation in a current of steam, and a dark brown precipitate which had formed was collected. Isolation of I'puranol, C23H3802(0H)2. The above-mentioned dark brown precipitate amounted to 30 grams, and consisted for the most part of a barium compound. It was treated with acetic acid, when a small portion remained undissolved, and this, after being dried, was crystallised from a mixture of pyridine and ethyl acetate. The substance then separated in colourless, microscopic needles, melting at 285—290°, and was identified as ipuranol. (Found, C = 72’2; H = 10'6. Calc., C = 72'6; H = 10'5 per cent.) When heated with acetic anhydride the substance yielded diacetylipuranol, which, after crystallisation from ethyl acetate, melted at 162°. The liquid from which the above-mentioned dark brown precipi¬ tate had separated was treated with carbon dioxide for the removal of the excess of barium, and, after filtration, dilute sulphuric acid was added until a precipitate just ceased to be produced, any excess of the mineral acid being carefully avoided. The liquid was again filtered, and then distilled in a current of steam until volatile acids ceased to pass over. Isolation of d-a-Methylhutyric and Tiglic Acids. The above-mentioned distillate, which amounted to about 6 litres, was neutralised with sodium carbonate, and concentrated to a small volume, then acidified, and extracted with ether. The ethereal liquid was dried, and the solvent removed, when a quantity (50 grams) of a colourless liquid was obtained, which was distilled under the ordinary pressure. The main portion passed over between 160° and 200°, whilst the last fraction (1'5 grams), which