Chenopodium oil. Pt. 2, The hydrocarbon fraction / by T.A. Henry and H. Paget.

  • Thomas Anderson Henry
Date:
[1925.]
Catalogue details

Licence: Public Domain Mark

Credit: Chenopodium oil. Pt. 2, The hydrocarbon fraction / by T.A. Henry and H. Paget. Source: Wellcome Collection.

    10/16 (page 1656)
    oil, which, after drying, was distilled under reduced pressure, yielding an oil, b. p. 138—154°/19 mm., and a hard, pitch-like residue, which decomposed on further heating. The oil, after standing in solution in ether over potassium carbonate, was re¬ distilled in two fractions, b. p. 110—120°/15 mm. and 120— 136°/15 mm. Both were pale yellow, viscous oils having a faint carvone-like odour; they yielded no solid derivatives with phenyl- carbimide or 'p-nitrobenzoyl chloride, but on addition of serni- carbazide in aqueous acetic acid solution were converted in the course of 3 days into semi-solid masses, which, when rubbed with alcohol, became crystalline, m. p. 140° (air-dry) and 194° when completely dried at 100° ; after recrystallisation from boiling alcohol, they melted at 157° (air-dry) or 204° (dried at 120° in a vacuum), and these melting points were unchanged after a further crystal¬ lisation from alcohol. The acetic acid of crystallisation (see below) persists when the air-dry substance is crystallised from boiling alcohol, but if the dried substance is recrystallised from alcohol or boiling water the product obtained melts at 204° and is anhydrous. From all solvents the substance forms rosettes of transparent prisms [Found : loss on drying at 120° in a vacuum, 21-2%. CiiH1902N3,C2H402 requires loss- (acetic acid), 21-05%. Found in dried material: 0,58-6,58-7; H, 8-6, 8-4; N, 19-2. CnH1902N3 requires C, 58-6; H, 8-5; N, 18-6%]. The substance is therefore a semicarbazone of a product, C10H16O2, probably a keto-alcohol. When the semicarbazone is formed in presence of alcohol and acetic acid, or when it is repeatedly boiled with water, there is formed a base which has only been isolated, as the acetate, minute rosettes of needles, m. p. 206°, from water by slow evaporation, and the picrate, brilliant yellow needles, m. p. 158°, from acetone or acetone and benzene. This differs from the semicarbazone by the elements of a molecule of water [Found (i) in acetate: C, 57-5, 58-2; H, 8-3, 8-1. C11H170N3,C2H402 requires C, 58-05; H, 7-8%. Found (ii) in picrate : N, 18-6. C11H170N3,C6Ho(N0o)3*0H requires N, 19-3%]. It is clear from this that the semicarbazone readily undergoes internal condensation, losing a molecule of water, and on this account it is regarded as having the constitution represented by formula (VI), and the base CnH17ON3 formed from it as having formula (VII). Only part of the oil reacts with semicarbazide solution and after the whole of the semicarbazone has been separated the mother- liquor on dilution with water yields a thick oil, which can be extracted with ether. This could not be induced to crystallise, nor could it be distilled without some decomposition. It appears,