The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power.

  • Barrowcliff, Marmaduke.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power. 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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    (6 grams KMnO^). Oxidation rapidly ensued with the development of heat, all the permanganate added being reduced. The acids were then extracted, converted into their methyl esters, and the latter distilled, when practically all passed over between 200 and 210°/15 mm. This fraction was analysed : 0-1396 gave 0-3394 CO^ and 0-1316 HgO. C = 66-3 ; H = 10-5. C]r,H2gO^ requires 0 = 66-2 ; H = 10-3 per cent. CieHgoO, „ 0 = 67-1; H= 10-5 „ On standing, this fraction deposited a solid ester, which was collected and hydrolysed. The acid thus obtained, after several crystallisations, melted at 124°, and was identical with ?i-dodecanedicarboxylic acid, [0H2]i2(002H)2, which had previously been separated from the pro- ducts of the direct oxidation of chaulmoogric acid. It was evident, however, from the analysis of the above fi-action, that it also contained the ester of ^i-undecanedicarboxylic acid. Fraction 260—270°/15 mm.—This was spread on a porous plate to remove a little adhering oil, and then crystallised from methyl alcohol. A further quantity of the ester of the ketonicacid, melting at 66°, was separated from it, but the greater portion melted at 38°, and this was analysed : 0-1167 gave 0-2790 CO2 and 0-1033 H2O. 0 = 65-2; H = 9-8. ^21^38^6 J^equires C = 65-3 ; H = 9-8 per cent. This ester thus agreed in composition and melting point with the methyl ?t-pentadecane-aa'y-tricarboxylate previously obtained, and a mixture of the two showed no diminution in melting point. Action of Hydrogen Bromide on Ethyl Chaulmoograte. One hundred grams of ethyl chaulmoograte were dissolved in 500 c.c. of light petroleum (b. p. 40—50°), and the solution, kept cool by means of ice, was saturated with dry hydrogen bromide. After remaining overnight, the solvent was removed by aspirating a current of dry air through the liquid under diminished pressure. The ethyl hroinodihydrochaulmoograte thus obtained was a heavy, pale yellow liquid, having an agreeable odour. In moist air it slowly decomposed, evolving hydrogen bromide and becoming black. For the purpose of analysis a portion was repeatedly exposed to a gentle heat, and then placed in a vacuum desiccator containing paraffin wax and caustic potash. 0-1047 gave 0-2367 CO^ and 0-0892 HgO. C=6l-7; H = 9-5. CjgHgYOgBr requii’es C = 61-7 ; H = 9-5 per cent. cf20°/20°= 1-0778.
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