The resolution of benzoyloscine / by Frank Tutin.

  • Tutin, Frank.
Date:
1910
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: The resolution of benzoyloscine / by Frank Tutin. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    6/8 (page 1796)
    179(3 It was again crystallised as before, when it seemed much less soluble, and melted at 238—244°. 0 3982, made up to 20 c.c. with water, gave aD +2°4' in a 2-dem. tube, whence [a]D + 5T90; [M]t) + 295-8°. When recrystallised a third time, this salt yielded handsome, glistening needles, which melted sharply at 246—246'5°. 0 4092, made up to 20 c.c. with water, gave ctu + 2°8' in a 2 dcm. tube, whence [a]D + 52T°; [M]D +297 0°. This salt was evidently that of the dextrorotatory component of the racemic base, and since, as shown below, it yielded d-oscine on hydrolysis, it must be designated 6 enzoyl-d-oseine d-bromocamphor- sulphonale. Repeated crystallisation caused no further change in its melting point or rotatory power: 0T437 gave 0 2767 C02 and 0 0800 H,0. C = 52'5-; H = 62. CI5H17OsN,C]0H16O4BrS requires 0 = 52 6; H = 6'7 per cent. The molecular rotation of benzoyl-d-oscine, calculated from that of its f/-bromocamphorsulphonate, is [M]D + 26 0°, whence the basic ion has [a]D + 10 0°. A small quantity of the above-described salt of benzoyW-oscine was treated with sodium carbonate, the base extracted with chloro- form, and examined polarimetrically, when a reading of + 0°25' was obtained. It was evident, therefore, that the base could be obtained in the free state without suffering complete racemisation A larger quantity of the salt was then decomposed, and the resulting base dissolved iu 20 c.c. of 50 per cent, alcohol, when it had on + 0°49' in a 2-dcm. tube. Ten c.c. of the solution were subsequently found, on titration, to contain 0T172 of base, whence Mu +3'5°; [MJU + 9'75°. The fact that the value thus obtained for the rotation of bcnzoyl-d-oscine is lower than that previously calculated for the basic ion of benzoyl-<f-oscine <7-bromocamphor- sulphonate ([a]D +10 0°) may be due, in part, to racemisation, but it is probably largely owing to the fact that the free base is incom- pletely ionised when dissolved in 50 per cent, alcohol (compare Carr and Reynolds, this vol., p. 1328). Attempts were made to isolate bcnzoyl-l-oscine d-bromocamphor- sulphonate, but without success. A fraction of salt, melting at 219—227°, was, however, obtained, the basic ion of which had [M]d — 4’7°. Benzot/l-d-oscine hydrochloride was prepared from the correspond- ing cf-bromocamphorsulphonate by double decomposition. It formed colourless needles, melting at 283—284°. Bcnzoyl-d-oscine nitrate was similarly prepared. It was very sparingly soluble in water, and crystallised in irregular prisms/ '