Improvements in the manufacture of salicylide or salicylic anhydride.

  • F. Hoffmann-La Roche & Co.
Date:
1902
Catalogue details

Licence: Public Domain Mark

Credit: Improvements in the manufacture of salicylide or salicylic anhydride. Source: Wellcome Collection.

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    N» 20,188 A.D. 1901 Date cf Application, 9th Oct., 1901 Complete Specification Left, 1st July, 1902—Accepted, 7ih Aug., 1902 PEOVISIOmL SPECOLFICATIO^^. Improvement in the Manufacture of Salicylide or Salicylic Anhydride. I, Jasper Wetter, Cliartered Patent xigent, oJt & -39, Essex Street, Strand, London, do hereby declare the nature of this invention, a communication from the Firm of F. Hotfmann-la Koche & Co, Manufacturers, of Bale, Switzerland, to he as follows : — 5 The present invention has for its object, to produce pure salicylide suitable for pEarniaceutical and other purposes. If acetyl-salicylic acid is heated, it will yield salicylide already at a tempera¬ ture of 150—KiO, while giving otf acetic acid, but for completing the reaction, that is obtaining almost the theoretical quantity of salicylide, it is necessary to 10 work at a temperature between 200 and 210° C. The product thus obtained is a thick liquid when hot, but rapidly solidifies on cooling, so that it can be easily pulverised. In order to get rid of any aceto-salicylic acid adhering to it and also of recon¬ stituted salicylic acid, the product is repeatedly boiled wnth water or with dilute 16 spirits, and then dissolved in benzene, glacial acetic acid or chloroform, but preferably in acetone, after which the salicylide is precipitated out of the saturated acetone solution, preferably by pouring the solution into cold water. Pure salicylide is a white tasteless powder, practically insoluble in water and in ether, very sparingly soluble in hot alcohol. Its composition is represented 20 by the formula Cj 0^. ' If the salicylide is dissolved in boiling alcohol, the solution does not give the chemical reactions of salicylic acid. Salicylide is easily soluble in chloro¬ form, glacial acetic acid, benzene, and especially in acetone. M^en heated tn 110° C, it begins to sinter, at 130° it assumes the consistency of wax, at 1G0° it 25 is a thick liquid, and at 210° it begins to melt. It cannot be distilled without decomposition. When boiled with caustic alkalies, it rapidly and easily forms a salicylate and enters completely into solution. Alkali-carbonates decompose it, they will even decompose it in a 2—-5 ^?er €ent\ solution and at ordinary temperature if allowed 30 to stand for a considerable time. With the exception of concentrated sulphuric acid, wdiich converts it into sulpho-salicylic acid, acids will not split it up. In nitric acid it dissolves while forming trinitric-salicylide. The latter may be crystallised out of water in the shape of fine crystals which melt at 121.5° and taste very bitter. 35 Solutions of the nitric compound will not react with chloride of iron.^ The therapeutic value of pure salicylide is based on the fact, that it will not injure or disagree with the stomach, that it is free from disagreeable secondary effects, and will reconstitute salicylic acid only, when in contact with the w^alls of the duodenum. 40 Bated this 9th day of October 1901. FAIEEAX & WETTEE, Agents for the xVpplicant, [Price Scl]