Some new physiologically active derivatives of choline / by A.J. Ewins.

  • Ewins, Arthur James.
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: Some new physiologically active derivatives of choline / by A.J. Ewins. Source: Wellcome Collection.

    6/10 (page 371)
    (b) Formo-choline derivatives. Formo-choline itself was obtained by Schmidt and Litterscheid [1904] who were, however, unable to obtain either acetyl, benzoyl, or lactyl deri¬ vatives. Attempts by the writer to prepare the nitric ester of the base by methods similar to those employed for the preparation of the corresponding choline ester proved unsuccessful. It was found, however, that the ethers of formo-choline could readily be obtained by the action of trimethylamine on the corresponding iodomethvl ethers. For mo-choline methyl ether, OH . N(CH3)3CH20 . CH3. Iodomethyl ethyl ether I . CH20. CH3 was prepared according to the method employed by Henry [1893]. For purification it was washed with a very little ice water, dissolved in ether and dried over CaCl2. The ether was removed and the residue dis¬ tilled in vacuo. It boiled constantly at 39° under 20 mm. pressure. To the ethereal solution of the iodo-ether was added alcoholic trimethyl¬ amine, the mixture being kept cool by immersion in ice. A crystalline product consisting of a mixture of formo-choline methyl ether iodide, and trimethyl¬ amine iodide, separated immediately. The mixture was suspended in cold absolute alcohol. The bulk of the trimethylamine iodide remained undissolved and was filtered oh. The filtrate was evaporated to dryness, and the residue crystallised from a little alcohol by addition of ether. Formo-choline ether iodide was thus obtained as white glistening hygroscopic plates, melting at 84°. 0-1421; 0-1428 Ag I; 1 = 54-5. Calculated for CHgOCHaN(CH8)3l; I = 54-98. The flatinichloride crystallised from water in columnar aggregates of orange-red rhombic prisms, melting with decomposition at 234°. The salt was anhydrous and sparingly soluble in cold water, but readily soluble in hot water. 0-1028; 0-0322 Pt; Pt = 31-3. Calculated for (C6H14O.N)2PtCl6; Pt = 31-6. The aurichloride is moderately soluble in hot water, sparingly in cold. It crystallises in golden yellow needles melting at 135-136°. 0-1212; 0-0536 Au ; Au = 44-2. Calculated for C5H14ON AuC14 ; Au = 44’4. Formo-choline ethyl ether, OH . N(CH3)3CH20 . C2H5. Iodo-methyl ethyl ether, I . CH20 . C2H5, was prepared by a method analogous to that employed by Henry to obtain the corresponding methyl ether. On distillation in vacuo