The constituents of commercial chrysarobin / by Frank Tutin and Hubert W.B. Clewer.
- Tutin, Frank.
- Date:
- 1912
Licence: In copyright
Credit: The constituents of commercial chrysarobin / by Frank Tutin and Hubert W.B. Clewer. 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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![form, and the resulting liquid extracted successively with aqueous ammonium carbonate and sodium carbonate. During these opera- tions appreciable quantities of a nearly black, finely divided solid separated, which gave rise to the formation of troublesome emul- sions. Nothing crystalline could be obtained from the suspended solid matter, and no precipitate was formed on acidifying the filtered liquid obtained after shaking with the first-mentioned alkali. When, however, the filtered alkaline liquid obtained after shaking with aqueous sodium carbonate was acidified, a quantity (about 0 8 gram) of an orange-coloured powder separated. This was collected and recrystallised from dilute pyridine, when it formed orange-coloured needles (m. p. 252°), and was identified as emodin.* (Found, C = 66-5; H = 3-9. Calc., C = 66'7; H = 3 7 per cent.) The identity of this substance was further confirmed by its conversion into triacetylemodin, which formed slender, pale yellow prisms, melting at 194°. Emodi.ntridiphenylurethane, G'H-f C^H^C^fCO-NPho).).—With the endeavour to form derivatives of the new compounds subsequently described, experiments were conducted with the employment of diphenylcarbamyl chloride. Although these experiments proved unsuccessful as regards the new compounds mentioned, it was found in a preliminary experiment that emodin readily yielded a tridi- phenylur ethane, a compound which has not previously been described. A quantity (0'5 gram) of emodin was dissolved in pyridine, and the solution heated with 1‘4 grams of diphenylcarbamyl chloride according to Herzog’s method (Ber., 1907, 40, 1831). The resulting ■ tridiphenylurethane separates from a mixture of alcohol and pyridine in small, pale yellow, flattened needles melting at 193°: 0-1103 gave 0 3048 C02 and 0-0434 H20. C=75 4; H = 4‘4. C^H^OgNg requires C = 757; H = 43 per cent. Emodintridiphenylur ethane is readily soluble in chloroform, benzene, or pyridine, and moderately soluble in ethyl acetate, but it dissolves only sparingly in alcohol. Isolation of Chryeophanol,\ C15H]0O4. The original chloroform solution, from which the emodin had been removed, as above described, was evaporated, and the residue heated Since emodinanthranol is dissolved and oxidised when shaken with aqueous sodium carbonate, there is no proof that the emodin obtained from Arnroba powder :did not occur partly, or possibly wholly, as the corresponding anthranol. t The name chrysophanic acid was origiually applied to a product which is now known to have consisted of a mixture of a dihydroxyniethylanthraquinone, C15H10O4, und emodin monomethyl ether. More recently, it has been applied to the former](https://iiif.wellcomecollection.org/image/b22439377_0007.jp2/full/800%2C/0/default.jpg)
