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.
6/86 page 856
![The acid was therefore acetic acid, and examination of the other portions of the alcoholic distillate failed to reveal the presence of any other acid. The ethereal residue was fractionated first in a vacuum and finally under atmospheric pressure, the following fractions being obtained : 1. Boiling at 280—299°. Yield = 5 per cent. 2. „ „ 299° „ =90 3. „ „ 200—210° under 10 mm. pressure. Yield = 5 per cent. The liquid boiling at 299° was therefore pure, and on further fractiona¬ tion was found to distil almost completely at this temperature. It was quite free from nitrogen. Analyses were made of a number of specimens, with the following results : 1. 0*1608 gave 0*34 C02 and 0*1106 H20. C = 57’83; H = 7-65. 2.0-1822 „ 0-393 C02 „ 0-1266 H20. C = 58-83 ; H = 7*72. 3.0-22 „ 0-4712 C02 „ 0-153 H2Q. 0 = 58-41; H = 7*73. 4.0-239 „ 0*511 C02 „ 0-164 H20. C = 58-32 ; H = 7*62. C9H1404 requires C = 58-07 ; H = 7*53 per cent. The specific rotation of the pure liquid was determined with the following result: a16o= +22° ; £ = 50 mm. ; d 15°/15°= 1*1053 ; [a]i>'= +39-8°. The liquid was insoluble in water, but soluble in ether or alcohol, and had a peculiar, but not unpleasant, smell. On hydrolysis, it was found to be the ethyl ester of a dibasic or lactonic acid, as with phenolphthalein as indicator it required 2 molecular proportions of alkali to effect neutralisation. Acid C7H10O4, formed by Oxidation. The acid was formed from the ester by hydrolysing either with caustic potash or aqueous hydrochloric acid. It is a thick, slightly yellow oil which does not solidify at —21°, boils at 210—220° under 10 mm. pressure, and is freely soluble in water, ethyl alcohol, or benzene. All attempts to crystallise it failed. On analysis : 0-1826 gave 0*3514 C02 and 0-1094 H20. 0 = 52*48; H = 6 65. CfH10O4 requires 0 = 53*16 ; H = 6*33 per cent. When titrated in the cold with Nj 10 alkali, using phenolphthalein as indicator, 0*1678 required 10'7 c.c. Nj10 alkali. Calculated 10-6 c.c. When titrated by boiling, first with excess of alkali, and then titrating back with acid, while still hot, 0*2234 required 26-00 c.c. Nj 10 alkali. Calculated 28 2 c.c. The acid is therefore lactonic, and the formula may be written co2h-c4h9-co-o.](https://iiif.wellcomecollection.org/image/b30598667_0006.jp2/full/800%2C/0/default.jpg)
