The action of antimony trichloride upon diazotised diamines / by W.H. Gray.

  • Gray, William Herbert.
Date:
[1926.]
Catalogue details

Licence: Public Domain Mark

Credit: The action of antimony trichloride upon diazotised diamines / by W.H. Gray. Source: Wellcome Collection.

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    substituents have been entirely removed, is therefore still less stable. The acetylation of (IV) with acetic anhydride, already mentioned, takes place only in bright sunlight. If concentrated sulphuric acid is added, this is not necessary, but the acetylated product is a sulphur-containing diazonium compound, C10H13O5N3S. This is neutral, but is not a sulphate. Sulphuric acid is, however, slowly set free on boiling with dilute hydrochloric acid. The sulphur is immediately removed by various reagents (p. 3180) with formation of derivatives of p-acetylaminodiazobenzene. Experimental. The Action of Antimony Trichloride on Diazotised Acetyl-p-phenyl - enediamine.— Aeetyl-p-phenylenediamine (22*5 g.) was dissolved in a previously warmed mixture of 40% hydrochloric acid (36 c.c.) and water (465 c.c.), and the solution, after decoloration, was rapidly cooled to 12—14° and diazotised during 1 hour with sodium nitrite (10-5 g.) in water (150 c.c.). When diazotisation was carried out below 5°, a considerably poorer yield of antimony compound was obtained. Ice-cold 40% hydrochloric acid in excess (166 c.c.) was then added, followed by a filtered solution of antimony trioxide (19-7 g.) in 40% hydrochloric acid (49 c.c.), with vigorous stirring. A pale brown, crystalline precipitate separated, and was dried on a porous tile in the air until free from hydrochloric acid (yield, 38 g.). By adding the antimony trichloride in several portions, fractions differing in colour could be obtained; the last was very light-coloured, but although homogeneous in appearance, its antimony content and melting point, together with the action of methyl alcohol upon it (see below), showed that it was a mixture of the two compounds (I) and (VI), the former greatly predominating. No separation could be effected by straightforward fractional crystallisation; they were separated as described below. A certain amount of hydrolysis and diazoimine formation evidently occurs during the diazotisation. Sodium hydroxide in slight excess caused a characteristic decom¬ position with frothing and formation of sodium p-acetylamino- phenylstibinate. Di-(p-acetylaminobenzenediazonium Chloride)-Antimony Trichloride (I).—The pale-coloured fraction (see above) was extracted several times with cold methyl alcohol, which removed bright yellow material, raised the melting point, and lowered the antimony content from 22% to 20%. By a single recrystallisation of the undissolved portion from boiling methyl alcohol, the substance was obtained quite pure in colourless, square plates, m. p. 147° (corr.) (Found : Sb, 19-5; Cl, 28-8. C16H1602N6Cl5Sb requires Sb, 19-5; Cl, 28-4%).