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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    by filtration. Tbe filtrate was then concentrated and acidified with sulphuric acid, when a white, solid substance separated. This was extracted with ether, the ethereal liquid being washed, dried, and the solvent removed. The solid residue was then extracted with light petroleum, which removed a small amount of unchanged chaulmoogric acid. The portion insoluble in petroleum was crystallised repeatedly from warm benzene, then from acetone, ethyl acetate, and, finally, again from acetone, from which it separated in aggregates of fine needles, melting at 102°. 0*1068 gave 0*2680 C09 and 0T042 H20. C = 68*5; H = 10*8. 0-1112 „ 0*2782 C02 „ 0*1068 H20. 0 = 68*2 ; H = 10*7. Ci8H3404 requires C = 68*8 ; H = 10*8 per cent. Oxidation of Chaulmoogric Acid with Potassium Permanganate (O = 4—5 atomic equivalents). Formation of Formic Acid and Two Dibasic Acids, C1t7H30O4 and C1^H30O5. When chaulmoogric acid, dissolved in dilute aqueous potassium hydroxide, was oxidised at the ordinary temperature with an amount of permanganate equivalent to 4—5 atomic proportions of oxygen, the following substances were produced : (a) Formic acid, which was isolated in the form of its barium salt and the latter analysed. (b) A mixture of several other acids, which were converted into their ethyl esters. On distilling these under diminished pressure (10 mm.), they yielded the following fractions : (1) 210—220°; (2) 220—260°; (3) 260—270°; and (4) 270—280°, a very small amount. Fraction (1).—This, which became crystalline on cooling, was drained from a little adhering oil and then crystallised from methyl alcohol, from which it separated in shining leaflets, melting at 26—27°. 0*0724 gave 0*1882 C02 and 0*0710 H20. C = 70*9 ; H = 10*9. 0*0622 „ 0*1608 C02 „ 0*0606 H20. C = 70*5 ; H= 10 8. C2iH3804 requires C = 71*2; H = 10*7 per cent. 0’5140 required NaOH equivalent to 29*1 c.c. of a decinormal solution, instead of 29 c.c., the calculated amount for C15H28(C02Et)2 A silver salt of the corresponding acid was prepared from the sodium salt. 0*1728 gave 0*0718 Ag. Ag = 41*6. ^irH2804Ag2 requires Ag = 42*3 per cent. It was thus shown that the fraction of ester boiling at