The resolution of hyoscine and its components, tropic acid and oscine / by Harold King.
- King, Harold
- Date:
- 1919]
Licence: Public Domain Mark
Credit: The resolution of hyoscine and its components, tropic acid and oscine / by Harold King. Source: Wellcome Collection.
15/34 page 490
![mother liquors (together with quinidine Z-tropate), which was probably this salt in ah impure condition. d-Tropic Acid. Pure quinine r7-tropate (16 grams) was acidified with 50 c.c. ol 5 per cent, hydrochloric acid and completely extracted with purified ether. The crude acid so obtained (5'1 grams) melted at 127—128°, and had [a]D+77’2° in water (c = l). On recrystal¬ lisation from water, the melting point rose to 128 129°, and the rotation to [a]p +79°. After two more crystallisations, the melt¬ ing point remained unchanged, but the rotation rose to faJD + 81*6°. The yield was 3‘1 grams. <7-Tropic acid crystallises from water in delicate, lustrous scales, which become transformed on keeping in contact with the solution into elongated prisms of hexagonal cross-section. Both forms melt at 128—129° (129—130° corr.) and are anhydrous: 0'2014 was equivalent to 11*9 c.c. A/10-baryta. M.W. = 169. C9ni0O3 requires M.W. = 166. The specific rotation was determined in alcohol and in water. In water: c = 1*027 ; Z = 2-dcm.; aD + 1°40-6'; [a]D+81*60. In absolute alcohol: c = 0*997; 1 = 2-dcm.; aD+l°24'2/; [a]D+70*3°. c = 2*472 ; 1 = 2-dcm.; aD+3°33*l/; [a]D+71*8°. The specific rotation of the ion was determined by dissolving 0-200 gram of ^-tropic acid and 0*0638 gram of anhydrous sodium carbonate in water and making up to 20 c.c. The dissolved caibon dioxide was not removed : 1 = 2-dcm.; a+l°22*9'; [a]D for ion + 69*4°; [M]D for ion + 114-70. Gadamer (Arch. Pharm., 1901, 239, 294) has previously noted a fall of rotation of Z-tropic acid on converting into a salt, but has not followed it quantitatively. \-Tropic Acid. From Quinidine \-Tropate.—Four grams of pure quinidine Z-tropate, on treatment with hydrochloric acid (10 per cent.) and extraction with ether, gave P35 grams of Z-tropic acid, which, after three crystallisations from water, gave 0*5 gram melting at 128 129° (129—130° corr.). The specific rotatory power was determined in water, and was slightly less than that of the purest ^/-tropic acid : <• = 0-995; Z = 2-dcm.; cq, — 1°37'; [a]D—81-2°.](https://iiif.wellcomecollection.org/image/b30622074_0015.jp2/full/800%2C/0/default.jpg)
