The constituents of leptandra / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: The constituents of leptandra / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

    9/18 (page 1950)
    sparingly soluble in the usual organic solvents, and crystallises in small, prismatic needles, which melt at 178—180°. (Found, C = 61'0; H = 5‘8. Calc., C = 61'5; H = 5’6 per cent.) 0'3410, made up to 20 c.c. with pyridine, gave an + 0°22/ in a 2-dcm. tube, whence [a]D +10*7°. Dibenzoylmannitol has previously been obtained by Einhorn and Hollandt (.4nnalen, 1898, 301, 102), who recorded its melting point as 178°. On adding an excess of benzoyl chloride to a hot solution of mannitol in pyridine, according to the method of the last-mentioned investigators, a crystalline substance began to separate at once, which was evidently the dibenzoyl derivative. When, however, the liquid was heated a little longer, a vigorous reaction ensued, which soon subsided, and a perfectly clear solution was obtained. The product was then poured into water and extracted with ether, when a substance was obtained which melted at 149°, and proved to be hexabenzoylmannitol. Examination of the Resin (B). This was a dark brown, brittle mass, and amounted to about 350 grams, being thus equivalent to 6'2 per cent, of the drug. It was dissolved in alcohol, mixed with purified sawdust, and the mixture successively extracted in a Soxhlet apparatus with light petroleum (b. p. 35—50°), ether, chloroform, ethyl acetate, and alcohol. Petroleum Extract of the Resin. This was a dark brown mass, amounting to 24*5 grams. The extract was dissolved in ether, and the ethereal solution shaken with aqueous ammonium carbonate, which, however, removed only a small amount of resinous material, together with a trace of 3: 4-dimethoxycinnamic acid. The ethereal solution was then shaken with aqueous potassium carbonate, and the alkaline liquid acidified, when a quantity of black, tarry material was precipitated. This was distilled several times under diminished pressure, when a product was finally obtained which passed over between 220° and 240°/15 mm. as a light yellow oil, and partly solidified on cooling. The free acids thus obtained amounted to 3*7 grams, and wTere examined together with the combined acids which will subsequently be described. After treatment with potassium carbonate, as above described, t^e ethereal solution was shaken with aqueous potassium hydroxide, which, however, removed nothing. On finally evaporating the ether, a residue was obtained, ’which was hydrolysed by heating with an alcoholic solution of potassium hydroxide. The alcohol was then