The constitution of chrysophanic acid and of emodin / by H.A.D. Jowett and C.E. Potter.

  • Jowett, Hooper Albert Dickinson, 1870-1936.
Date:
[1903]
Catalogue details

Licence: In copyright

Credit: The constitution of chrysophanic acid and of emodin / by H.A.D. Jowett and C.E. Potter. 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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    residue was dissolved in a large volume of hot glacial acetic acid, the solution being boiled with animal charcoal. The crystals, which separated on cooling from the filtered solution, did not melt below 300°; they were crystallised twice from ethyl acetate and thus obtained as bright golden-yellow leaflets. The substance dissolved in concentrated sulphuric acid to a deep pink solution, and developed a brownish-red coloration in ammonia, a full red tint being produced in aqueous caustic alkalis ; it is only slightly soluble in aqueous sodium carbonate, forming a reddish-yellow solution. 0-0854 gave 0-2224 C02 and 0-0344 H20. 0 = 71-0; H = 4-5. 0-1164 „ 0-3030 C02 „ 0-0504 H20. C = 71-0; H = 4-8. C16H1204 requires C = 716 ; H = 4 5 per cent. The acetyl compound, C16H10O4(C2H3O)2, prepared by the action of acetic anhydride and sodium acetate, formed long, yellow, acicular crystals melting at 215°, and this melting point was not altered on recrystallisation. 0-0842 gave 0-2102 C02 and 0-0372 H20. C = 68-l ; H = 4-8. O20Hi6O6 requires 0 = 68-1 ; H = 45 per cent. The monomethyl ether, C1GHn04(CH3), was formed by heating the dihydroxydimethylanthraquinone at 100° for 2 hours in a sealed tube with equivalent amounts of sodium and methyl iodide dissolved in methyl alcohol. The product, which separated on cooling, was collected, washed with water, and repeatedly crystallised from hot ethyl acetate, the ether being thus obtained in golden-yellow, acicular crystals melting at 214—215°. 0-093 gave, by Zeisel’s method, 0-0702 Agl. OCH3 = 4-8. C1?H,404 requires OOH3 = 5-3 per cent. A dimethyl ether could not be obtained. The acetyl compound, C16H10O4(CH3)(C2H3O), prepared in the usual way with acetic anhydride and sodium acetate, when crystallised from absolute alcohol, formed light yellow, acicular crystals melting at 195—196°. 0-1012 gave 0-2580 C02 and 0-0440 H20. C = 69‘5 ; H = 4-8. 0-0946 „ 0-2412 C02 „ 0 0428 H20. C = 69-5; H = 5'0. C19H1G05 requires C = 70'3 ; H = 4'9 per cent. The formation of the monomethyl ether proves that the condensa- tion product contains only one hydroxyl group contiguous to th carbonyl, and as of the three isomerides possible by the condensation of two molecules of m-hydroxy-p-toluic acid only one fulfils this con