The constituents of the essential oil of American pennyroyal / by Marmaduke Barrowcliff.

  • Barrowcliff, Marmaduke.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The constituents of the essential oil of American pennyroyal / by Marmaduke Barrowcliff. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    terpene, mixed with some of the oxygenated constituents of the oil. In order to remove the latter as completely as possible, it was washed several times with 70 per cent, alcohol, when a small amount of liquid remained which was sparingly soluble in this solvent. It then yielded a small quantity of a crystalline nitrosochloride, melting at 103—104°, from which the corresponding nitrolbenzylamine, melting at 122°, was prepared. The presence of a small amount of ^-pinene in the oil was thus established. Identification of l-Methyl-Z-cyclohexanone. Fraction 165—170°.—This was a colourless, limpid liquid having an agreeable odour. It distilled for the most part at 166—168° and amounted to 87 grams : 0-1337 gave 0-3780 CO2 and 0-1324 H.p. 0 = 77-1 ; H = ll-0. d 16-5°/16-5° = 0-9006 ; an -0°10' in a 1-dcm. tube. This fraction, although consisting chiefly of an oxygenated sub- stance, evidently contained some pinene. Its solution in chloroform decolorised a considerable amount of bromine, hydrogen bromine being evolved. On treatment with hydroxylamine an oxime was obtained which distilled at 130° under 33 mm. pressure, and then slowly solidifled in fine needles melting at 41—43°. This melting point corresponds with that of an oxime obtained by Kremers {Pharm. Rundschau, 1891, 9, 130) from a fraction of hedeoma oil boiling at 168—171°, but which appears not to have been identified or further examined by him : 0-1073 gave 0-2585 COg and 0-0985 HgO. C = 65-7 ; H = 10-2. CyHjgON requires 0 = 66-1 ; H=10-2 per cent. A portion of the fraction was treated with semicarbazide hydro- chloride and sodium acetate, when a semicarbazone was readily obtained. After crystallisation from alcohol it was obtained in glistening plates melting at 182—183°; 0-1164 gave 0-2420 CO2 and 0-0919 Hp. 0 = 56-7; H = 8-8. OgH^pNg requires 0 = 56-8 ; H = 8-9 per cent. Nine grams of the semicarbazone were decomposed with dilute sulphuric acid and the liberated ketone distilled in steam. The distil- late was then extracted with ether, the ethereal solution dried, and the solvent removed, when a residue was obtained which distilled at 167—168° as a colourless, mobile oil: 0-1098 gave 0-3018 OOg and 0-1068 HgO. 0 = 75-0 ; H = 10-8. OylljgO requires 0 = 75-0 ; H= 10-7 per cent. d = 0-9154 at 20°/20°; 12°0' in a 1-dcm* tube, whence [a ]d -1-13-1°