The constitution of chaulmoogric acid : Pt. 1 / by Frederick B. Power and Frank H. Gornall.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1904.]
Catalogue details

Licence: In copyright

Credit: The constitution of chaulmoogric acid : Pt. 1 / by Frederick B. Power and Frank H. Gornall. Source: Wellcome Collection.

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    The value found, namely, 21‘020, is seen to approximate very closely to the third calculated value, 21T10, which is that for an ester having the formula C20H36O2, containing a closed ring and one unsaturated linking of an allylic nature. Refractive Rower. tn5-4°/4° 0-90637. H. 15-4°. 1 d ' ~TR Ha. . 1-46000 0-50752 156-315 H/?. ,. 1-46851 0-51691 159-208 Hr. .. 1-47404 0-52300 161085 Dispersion (Hy—Ha) = 4*770. Chaulmoogr amide, Ol7H31 *CO*NH2. The amide was prepared according to Aschan’s method (Ber., 1898, 31, 2344), which consists in first converting the acid into its chloride by treating it with phosphorus trichloride, and then pouring the product into well-cooled, concentrated, aqueous ammonia. The white solid thus formed was thoroughly washed with water, dried, and crystallised several times from hot ethyl alcohol. It melted at 106°. 0-1039 gave 0-2942 C02 and 0-1112 H20. 0 = 77-2 ; H = ll-9. CjgHgsON requires 0 = 77*4; H = ll*8 per cent. 4*3 grams in 100 c.c. of chloroform gave aD + l°14' in a 50 mm. tube, whence [a]‘ff + 57*3°. Ethyl Dibromodihydrochaulmoograte, C^H^BtyCO^Et. Seventeen grams of ethyl chaulmoograte were dissolved in 50 c c. of dry chloroform. To this solution, cooled below 0°, a solution of 9 grams of dry bromine in 30 c.c. of dry chloroform was gradually added in the absence of light; the bromine was rapidly absorbed and -without any evolution of hydrogen bromide. When all the bromine had been introduced, and after a lapse of several minutes, a permanent redness was apparent. After the removal of the slight excess of bromine by agitation with aqueous sodium hydrogen sulphite, the chloroform solution was washed, first with water, then with dilute aqueous sodium carbonate, again with water, and finally dried with calcium chloride. The chloroform was then removed by aspirating a rapid current of dry air through the liquid, which was maintained at 25°. The product was a nearly colourless oil, and was not markedly