The resolution of hyoscine and its components, tropic acid and oscine / by Harold King.

  • King, Harold
Date:
1919]
Catalogue details

Licence: Public Domain Mark

Credit: The resolution of hyoscine and its components, tropic acid and oscine / by Harold King. Source: Wellcome Collection.

    24/34 (page 499)
    Benz oyl-d-oscine H ydroc hi oriel e. • Pur© benzoyl-^-oscine bromocamphorsulphonate (2 8 grams) was triturated with 30 c.c. of water and three molecular proportions of sodium hydrogen carbonate. BenzoyWZ-oscine base appeared to separate in needles, which were immediately dissolved by chloro¬ form. The free base, on removal of the solvent, was exactly neutralised with Nj 10-hydrochloric acid, and, after filtering from a little greasy matter, was concentrated rapidly under diminished pressure to a very small volume. On keeping for a short time, the whole of the liquid became filled with perfectly formed rectangular leaflets, which in a few hours were completely transformed into fine needles. These were collected and washed with absolute alcohol. They amounted to IT grams, and melted and decom¬ posed at 280° (287° corr.) (Tutin gives 283—284°). The product was anhydrous. Its specific rotation was determined in dilute aqueous solution : c=:2’005; ?=2-dcm.; aD+28-35/; [a]D +11*79°; [M]D+34-83°. From this is calculated [a]D +13-4° for the benzoyl-^-oscinium ion, a value which compares favourably with the value + 12'9° calcu¬ lated above from the bromocamphorsulphonate. This value is somewhat higher than Tutin’s value, [a]D + 10-0°, which is obtained by calculation from the value [M]D + 297-0° for benzoyl-<7-oscine bromocamphorsulphonate. Hydrolysis of Benz oyl-d-oscine. With Hydrochloric Acid.—The solution just employed (20 c.c.), containing 0*4001 gram of benzoyl-^-oscdne hydrochloride, was treated with 9*7 c.c. of 31 per cent, hydrochloric acid, thus bring¬ ing the volume approximately to 30 c.c. and the strength of the acid to 10 per cent. The rotation was observed, and the solution was then boiled gently to hydrolyse the benzoyl-<7-oscine, the rota¬ tion being observed at intervals, just as is described under the hydrolysis of ^-hyoscine (p. 507). Initial reading. + 20/; Z = 2-dcm. After 1 hour’s boiling, + 20'5/. After 3 hours’ boiling, +220/. Hydrolysis was now complete, as there was a copious separation of benzoic acid, and the solution gave no turbidity with Mayer’s reagent. The observed rotation is therefore due to the <Aoscinium ion, and the final value, +22r, corresponds with a specific rotation of the e?-oscinium ion of + 26°, which is of the same order as that