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

  • Power, Frederick B. (Frederick Belding), 1853-1927
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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    ether, and the ethereal solution shaken with io per cent, sulphuric acid. As nothing was removed by this treatment, the ethereal liquid was repeat¬ edly extracted with a strong solution of sodium carbonate. The alkaline liquid thus obtained possessed a dark greenish color, and had the char¬ acters of a soap solution. It was acidified with sulphuric acid, when a sticky oil was precipitated, which was extracted with ether. On evap¬ orating the ethereal liquid a mixture of acids was obtained, which amounted to more than one-half of the original petroleum extract, and when freed from solvent, formed an extremely sticky, soft mass. It possessed a strongly acid reaction, and could be distilled under dimin¬ ished pressure without suffering decomposition, but this operation was ren¬ dered extremely difficult on account of the viscous nature of the material. The crude mixture of acids was therefore dissolved in about six times its volume of warm methyl alcohol, when, on allowing the solution to stand, it deposited a small amount of a crystalline solid. This was collected on a filter, and recrystallized from ethyl acetate, when it was found to melt at 81-82° C. It was analyzed with the following result: 0.0993 gave 0.2871 C02 and 0.1176 H20. C — 78.9; H— 13.2. C27H5402 requires C = 79.0; H = 13.2 per cent. This acid agrees in composition with cerotic acid, and is probably iden¬ tical with it, although the observed melting-point (81-82° C.) is some¬ what higher than that recorded (79° C.) for the latter acid. The acids contained in the methyl alcoholic filtrate from this solid acid were converted into their methyl esters by passing dry hydrogen chloride into the boiling liquid for two hours. The resulting esters were isolated in the usual manner, and repeatedly submitted to a systematic process of fractional distillation under a pressure of 20 Mm., when the following fractions were collected: (I) About 150-200°; (II) 200-215°; (III) 215-225°; (IV) 225-230°; (V) 230-235°; (VI) 235-240°; (VII) 240-245°; (VIII) 245-250°; (IX) 250-260°; (X) 260-270°; (XI) above 270° C. / 20 Mm. All these fractions possessed a brownish-yellow color, although No. I, on standing, rapidly darkened. The lower fractions were fairly mobile liquids, but with the increase of temperature at which the fractions were collected their viscosity also became progressively greater, the last two fractions being sticky solids. The results of the examination of the vari¬ ous fractions indicated that they represented an extremely complex mix¬ ture, as will be seen by reference to the following table :