The constitution of pilocarpine / by Hooper Albert Dickinson Jowett.
- Jowett, H. A. D. (Hooper Albert Dickinson)
- Date:
- [1900-1905]
Licence: In copyright
Credit: The constitution of pilocarpine / by Hooper Albert Dickinson Jowett. Source: Wellcome Collection.
4/86 page 854
![The hydrochloride was obtained by boiling the methyl-hydroxide with dilute hydrochloric acid, but neither this salt nor the nitrate has yet been crystallised. The base is soluble in water but insoluble in chloroform, thus differing from isopilocarpine, which is miscible with this solvent. Methylisopilocarpine was heated with excess of methyl iodide, and the latter removed by distillation ; the syrupy residue was then treated with moist silver oxide and filtered. After boiling with dilute hydro¬ chloric acid, it yielded a crystalline pi crate and platinichloride melting at 129° and 213° respectively, or a few degrees lower in each case than the corresponding salts of methylisopilocarpine. On analysis, it was found that further methylation had not taken place and that the base was unaltered methylisopilocarpine. 0*225 platinichloride gave 0*0514 Pt. Pt = 22*84. [C11H15(CH3)02N2]2,H2PtCl6 requires Pt = 22*87 per cent. Further heating with methyl iodide and subsequent decomposition produced a similar result, the platinichloride melting at 212° and containing Pt = 22*54 per cent. It follows therefore that by the action of methyl iodide only monomethylisopilocarpine can be pro¬ duced. The methiodide prepared as above, was treated with 20 per cent, caustic potash solution in a sealed tube for 4 hours at 150°, and the vola¬ tile bases collected and converted into the hydrochloride. The salt was entirely soluble in absolute alcohol and was precipitated in four fractions with platinic chloride. These platinichlorides were analysed with the following results: Fraction 1. 0*2226 gave 0*0916 Pt. Pt = 41*15. „ 2. 0*3258 „ 0*134 Pt. Pt = 41*13. „ 3. 0*1788 „ 0*074 Pt. Pt = 41*38. „ 4. 0*1654 „ 0*0688 Pt. Pt = 41*59. (CHs*NH2)2,H2PtCl6 requires Pt = 41*3 per cent. The base was therefore homogeneous and was methylamine. The explanation of these results would seem to be that there exists in isopilocarpine the group !NH, which reacts with methyl iodide, forming F!NH,CH3I; this with moist silver oxide yields P!NH,CH3*OH, which on boiling with dilute acids loses water and forms Itm*CH3. The methylated base can react with methyl iodide, forming K!NCH3,CH3I, but on further treatment, the methyl iodide is elimi¬ nated, leaving the original base R!NCH3. With caustic potash, the nitrogen of this complex is eliminated as methylamine, together with the same base formed from the other nitrogen group.](https://iiif.wellcomecollection.org/image/b30598667_0004.jp2/full/800%2C/0/default.jpg)
