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.

    15/26 (page 569)
    0 0935 gave 0-2234 CO, and 0-0859 H20. C = 65-2 • H = 10-2. 0-1208 „ 0-2879 C02 and 0-1098 H20. C = 65-0 ; H = 101. Ci1H2604 requires C = 65’l ; H = 10*1 per cent. This substance agrees in composition and melting point with ?i-dodecanedicarboxylic acid, [CH2]12(C02II)2, obtained by Brown and Walker by the electrolysis of potassium ethyl suberate (Anncilen, 1891, 261, 123). In order to confirm its identity with the above- mentioned acid, its diethyl ester was prepared. This was found to have the same melting point (28°) as a specimen of the synthetic ester which was kindly supplied to us by Professor A. Crum Brown, and a mixture of the two esters showed no diminution in melting point. A mixture of the two acids likewise melted at the same temperature (124°) at which each separately fused. The fraction (6), b. p. 200—205°/15 mm., deposited no solid ester, even on long standing. It was therefore hydrolysed and the acids extracted. These melted indefinitely at 93—105°, but after several crystallisations from ethyl acetate an acid was obtained which separated in small, glistening needles, melting at 112°, and this melting point was not changed by further crystallisation : 0-1093 gave 0-2553 C02 and 0 0956 H20. C = 63-7; H = 9 7. 0-1158 „ 0-2700 C02 „ 0-1029 H20. C = 63-6 ; H = 9 9. C]3H2404 requires C = 63'9; H = 98 per cent. This substance agrees in composition and melting point with the brassylic acid, C13II2404 [regarded as w-undecanedicarboxylic acid, [CH2]u(C02II)2], obtained by Grossmann by the oxidation of behenolic acid, and is undoubtedly identical with it (Ber., 1893, 26, 645). From the fraction of esters (a), boiling below 200°/15 mm., of which after several oxidations further quantities were accumulated, adipic, ?i-pimelic, and suberic acids were isolated, whilst higher members of the same series were also found to be present. It was ascertained, however, by some other experiments that these acids were produced by the long continued action of permanganate on the above-mentioned w-undecane- and ?i-dodecane-dicarboxylic acids. Fraction 220—260°/15 mm.—This was small in amount (8 grams), and consisted of a mixture of the constituents of the fraction boiling below 220°/15 mm. and those of the fraction of higher boiling point. Isolation of a Tricarboxylic Acid, {n-Pentadecane-ady-tri¬ carboxylic Acid). Fraction 260—270°/15 mm.—This fraction, which was the largest obtained, crystallised and became almost completely solid on standing. It was drained on a porous plate, to remove a small quantity of