Chenopodium oil / by Thomas Anderson Henry and Humphrey Paget.

  • Thomas Anderson Henry
Date:
[1921.]
Catalogue details

Licence: Public Domain Mark

Credit: Chenopodium oil / by Thomas Anderson Henry and Humphrey Paget. Source: Wellcome Collection.

    5/16 page 1716
    consisted almost wholly of hydrocarbons; this was added to fraction (a), which then formed about 30 per cent, of the whole oil. Examination of the Hydrocarbon Fraction. Acids.—On repeated agitation with 5 per cent, solution of sodium carbonate, the fraction yielded 0*9 per cent, of oily material having the characteristic odour of the lower fatty acids. This was converted into silver salts by« neutralisation and precipitation in three portions with silver nitrate (Found : Ag = 56-27, 55-8, 57-6- Silver butyrate, C4H702Ag, requires Ag = 55-4 per cent.). Methyl Salicylate.—On further agitation of the fraction with 4 per cent, solution of sodium hydroxide, there was obtained on acidification 1-5 per cent, of a red oil, which on standing solidified in part, owing to the separation of salicylic acid (m. p. 156°), and the rest of the acid was removed by shaking the liquid portion with sodium carbonate solution. The liquid portion then boiled at 220°/755 mm., gave a benzoyl derivative, m. p. 83°, and was there¬ fore methyl salicylate; the salicylic acid is no doubt formed by the action of the alkali on the ester during extraction. As no evidence of the presence of other oxygenated compounds could be obtained, the mixture was then redistilled several times through a six-bulb Young dephlegmator, which separated it into three fractions boiling at 166—173°, 174—177°, and 177—180° under*765 mm. pressure. The middle fraction formed the bulk of the mixture, and this, on redistillation, was found to consist of a product having the following constants : b. p. 176-5—177°/765 mm.; d%l 0-8491; [a]“ —18-09°; n'fj 1-48320. It had a slight lemon- like odour, and its solution in acetic anhydride gave a transient, bluish-red coloration with sulphuric acid. This product was pre¬ pared without difficulty from all six oils, and in spite of its constant boiling point was subsequently found to be a mixture of at least three hydrocarbons. The results of the analysis (Found : C = 88-14, 88-16, 88-63; H = 11-40, 11-10, 11-21) agree fairly well with those required for a mixture of terpenes, C10H16, with cymene, C10H14, in about equal proportions (namely, C = 88-9; H = 11-08 per cent.), and further evidence was obtained later of the presence of approxi¬ mately this quantity of cymene. Attempts to effect a further separation by distillation at different pressures through a twelve-bulb Young dephlegmator were unsuccessful. Identification and Removal of oi-Terpinene.—Further separation of the mixture by physical means having failed, recourse was had to the identification of the components and attempts to eliminate
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