Chemical examination of grindelia. Pt. 2 / by Frederick B. Power and Frank Tutin.

  • Frederick Belding Power
Date:
[1907?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of grindelia. Pt. 2 / by Frederick B. Power and Frank Tutin. Source: Wellcome Collection.

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    previously obtained, and is presumably cerotic acid, although the pos¬ sibility of its being a higher homologue of the latter is not excluded. The product obtained on evaporation of the ethereal extracts of the alkaline liquid was shown in the previous communication to contain hentriacontane, CnH64, and a small amount of a phytosterol (m. p. 1660 C.). On submitting this product to fractional distillation under dimin¬ ished pressure, evidence has now been obtained that a small quantity of a hydrocarbon other than hentriacontane is also present. This second hydrocarbon melts at a temperature lower than that at which the one previously isolated fuses, but it could not be isolated in a state of purity. The alkaline liquid from which the unsaponifiable matter had been re¬ moved was acidified with sulphuric acid, and the acids which separated were extracted by means of ether. The ethereal solution of these acids was evaporated to a small bulk, and a considerable volume of light petro¬ leum then added, which caused the separation of a small amount of a brown, resinous product. This product, from which the clear liquid was decanted, was heated with methyl alcohol and dry hydrogen chloride, when it afforded a little resin and a viscous mixture of esters resembling the higher fractions of the esters obtained from the free acids previously described. The clear petroleum liquid was evaporated, and the residual acids converted into their methyl esters in the manner above described. The product thus obtained was not nearly so large in amount as the esters prepared from the free acids, but resembled the latter esters in its general properties. It was distilled under a pressure of 20 Mm., when the follow¬ ing fractions were collected: (I) Below 210°; (II) 210-230°; (III) 230-240°; (IV) 240-250° ; (V) 250-260°; (VI) above 260° C. / 20 Mm. Fractions II, III, and IV were the largest, the remainder being only small in amount. The specific rotations of these three principal fractions varied from [a]D—20.o° to—22.6°, and their densities from 0.9422 to 0.9844 at 20° C. All the fractions were obviously mixtures, and appeared to contain esters similar to those prepared from the free acids. On analysis, fraction II gave C = 76.3; H = 11.1 per cent., and when hydrolysed it yielded an oily acid, which, on standing, deposited a small quantity of a crystalline solid. This substance was separated and re- crystallized, after which it melted at 62° C., and appeared to be identical with the solid acid obtained from fraction III of the esters of the free acids. The amount of crystalline acid isolated in this latter case was, however, rather larger than that previously obtained. It was analyzed with the following result: 0.1069 gave 0.2968 CO., and 0.1211 II20. C — 75.7; H — 12.6. C,6H,202 requires C = 75.0; H = 12.5 per cent. C1sH3602 requires C = 76.1; H = 12.7 per cent. This crystalline solid would, therefore, appear to be a mixture of palmitic and stearic acids.
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