The constitution of pilocarpine / by Hooper Albert Dickinson Jowett.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[1900-1905]
Catalogue details

Licence: In copyright

Credit: The constitution of pilocarpine / by Hooper Albert Dickinson Jowett. Source: Wellcome Collection.

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    The non-basic product of the action of potash on methylisopilo- carpine is under investigation. Nitrous acid appears to have no action on isopilocarpine. Oxidation of Isopilocarpine with Permanganate. In the preliminary account of this reaction (loc. cit.), it was shown that the bases formed were ammonia and methylamine, and that two oils had been isolated, one having the properties of a lactone. Further investigation has shown that, in addition to a small quantity of acetic acid, an almost theoretical yield of a new acid, C7H10O4, is obtained. Experiments were made with varying amounts of permanganate, but the best results were obtained when 6 molecular proportions were used, the yield then amounting to 70 per cent, of the theoretical. The reaction may be expressed by the following equation : CnH1602N2 + 70 + H20 = NH8 + CH3-NH2 + C7H10O4 + 3C02. The details of one experiment may be given. Fifty-four grams of pure isopilocarpine nitrate, dissolved in a litre of water, were oxidised at 80° by the gradual addition of 188 grams of permanganate dissolved in 5 litres of water, the whole being kept thoroughly stirred by a turbine. The manganese dioxide was removed by filtration and thoroughly washed with hot water, the colourless filtrate and washings evaporated to a low bulk, made alkaline with caustic soda, and then distilled until the distillate was no longer alkaline. The residue was neutralised with hydrochloric acid, evaporated to dryness, mixed with sand, thoroughly dried, and then extracted with hot absolute alcohol in a Soxhlet apparatus. The alcoholic liquid, after saturation with hydrogen chloride, was allowed to stand, then boiled in a reflux apparatus for 2 hours, and distilled on the water-bath. The distillate had the distinct odour of ethyl acetate, so the first fractions were collected separately. The residue, after removal of the alcohol by distillation, was thrown into water, the acid liquid extracted several times with ether, the ethereal liquid washed with water until free from acid, dried over calcium chloride, and distilled to remove the ether. The first fraction distilled from the alcoholic solution was hydrolysed with caustic potash, and the alcohol removed by evaporation; the residue was then dissolved in water, acidified with dilute sulphuric acid, and distilled. The crystalline barium salt obtained from the acid distillate was converted into the crystalline silver salt by treatment with silver nitrate solution, and on analysis the following result was obtained : 00584 gave 0,0376 Ag. Ag = 64‘4. C2H302Ag requires Ag = 64’67 per cent.
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