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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    this composition, the formation of isobutyric acid would leave only one formula possible, namely, (CE,)2CH-CH-CH-002H. 6—CO The stability of the compound is remarkable, if it is the lactone of a /3-hydroxymalonic acid ; the formation of isobutyric acid, however, does not admit of the possibility of its being a y lactone, for if that were the case, acetone should be formed on oxidation, whereas careful search failed to detect it. The reactions described in the preceding paragraphs may be repre¬ sented as follows : (CH3)2CH> CH> CH> C02Et -> (CH3)2CH-CHBr-CH(C02Et)2 0—CO — (CH3)2CH- CH : C(C02Et)2 — (CH3)2CH-CH(0H)-C(0H)(C02H)2 — (CH3)2CH- co2h + co2. Experiments were made with pilocarpine to obtain the bromoethyl ester, by treatment with phosphorus pentabromide, but the basic character of pilocarpine interfered with the reaction, and a negative result was obtained. Fusion of Isopilocccrpine with Caustic Potash. Chastaing (Compt. rend., 1882, 94, 223) has described the fusion of pilocarpine with caustic potash, and stated that the products of the reaction were methylamine, carbon dioxide, butyric acid, and traces of acetic acid, and that the reaction may be represented by the equation 2CnH1G02N2 + 2H2Q = 2C02 + 4C4H802 + 4CH3*NH2 + 02, The analytical numbers quoted for the platinichloride * prove, how¬ ever, that he was working with a mixture of ammonia and methyl- amine, and no details are given of the identification of butyric or acetic acids. In the preliminary account of this reaction (loc. cit., 496), the bases formed were proved to be ammonia and methylamine, and the acids yielded a silver salt, which contained a higher percentage of silver than required for silver butyrate. The reaction has been further investigated. Five grams of pure isopilocarpine were fused with 50 grams of caustic potash, and the fused mass, after cooling, dissolved in water acidified with sulphuric acid, and distilled with * Found Pt = 42‘5 per cent. (NH3)2,H2PtCl6requires Pt=43,9and(CH3,NH2)2,H2PtC]6requiresPt = 41,3 percent.