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.

    18/86 (page 587)
    A determination of the specific rotation gave the following result : <= +1°; 1 = Idem.; c = 2*584 ; [a]if = + 38-7°. For isopilocarpine nitrate [a]D= +35*7°. On analysis: 0-112 gave 0*1986 C02 and 0*064 H20. 0=48-4; H = 6‘3. CnH]602N2,HN03 requires C = 48*6 ; Ii = 6*3 per cent. The picrate, prepared in the usual way, melted at 161° (corr.); the platinichloride, which melted at 227°, was analysed, with the following result: 0-0228 gave 0 0054 Pt. Pt = 23*68. (CnH1602N2)2,H2PtCl6 requires Pt = 23*58 per cent. (2) By Zinc and Glacial Acetic Acid.—This is the most convenient method for carrying out the reduction. Dibromoisopilocarpine was dissolved in a convenient quantity of glacial acetic acid, zinc dust added, and the mixture kept at 60—70° for 12—24 hours. The solution was diluted with water, filtered, the filtrate made alkaline with ammonia, and extracted with chloroform. After removing the chloroform by distillation, a residue was obtained which yielded a crystalline nitrate melting at 159° (corr.) and a crystalline picrate melting at 16F (corr.). The physical constants and analyses just given prove that the base formed by the reduction of dibromoisopilocarpine is identical in all respects with the original base, isopilocarpine. Oxidation of Dibromoi&opilocarpine with Permanganate. When dibromompilocarpine is oxidised with a limited quantity of permanganate, the bromine is eliminated as hydrogen bromide, and, in addition, two acids are formed, pilopic acid, C7H10O4, previously ob¬ tained by the oxidation of ?’sopilocarpine with permanganate, and a new acid, pilopinic acid, C8Hn04N, together with methylamine and a small quantity of ammonia. Pilopinic acid is readily oxidised to ammonia and pilopic acid, and hence is only obtained in small quan¬ tity, the best yield being 20 per cent, of the theoretical, an equal amount of pilopic acid being formed at the same time. Experiments were made with varying amounts of permanganate, and under different conditions, but the best results were obtained with 3 molecular pro¬ portions of permanganate. The formation of pilopinic acid may be expressed by the following equation : CnH1402N2Br2 + 40 + 2H20 = C8Hn04N + NH2-CH3 + 2C02 + 2HBr. The reaction was carried out as follows. To 36 grams of potassium permanganate dissolved in 600 c.c. of water, 24 grams of finely