Orientation of the nitro- and arylazo-glyoxalines. Fission of the glyoxaline nucleus / by Robert George Fargher.

  • Fargher, Robert George.
Date:
1920.]
Catalogue details

Licence: Public Domain Mark

Credit: Orientation of the nitro- and arylazo-glyoxalines. Fission of the glyoxaline nucleus / by Robert George Fargher. Source: Wellcome Collection.

    11/14 (page 678)
    develops on addition to sodium-/3-naphthoxide. An ammoniacal solution of silver nitrate is reduced in the cold. With Fehling’s solution, a bluish-green precipitate is formed, which becomes dark green on warming. With sodium nitroprusside in presence of sodium hydroxide, a reddish-brown colour develops, which changes to green on acidification with acetic acid, and is discharged by excess of the reagent. The aqueous solution reduces cold aqueous acid permanganate. The base reacts with benzaldehyde, with formation of a benzylidene derivative, which was not obtained in a crystalline condition. The properties and composition of the base point, therefore, to its being 2-methyl-4:-(2,-amino-5l-bromophenyl)- d-glyoxalone (XII, p. 670). The picrate separates from water in glistening, orange plates which, when dried in the air, melt at 157° (corr.), sintering slightly above 140°. It appears to contain two molecules of water of crystallisation, one of which is lost on drying at 60° in a vacuum. Found: in air-dried material, N = 15*65; loss at 60° in a vacuum =3’4. In dried material, N = 16'2. CjoTIioONgBrjCgHgO-rNg^HgO requires N = 15*8. For loss of 1H20, H20 = 3'4 per cent. C10H10ON3Br,C6H3O7N3,H2O (5151) requires N = 16-3 per cent. After the separation of most of the above hydrochloride, ammonium chloride began to deposit, and a careful fractionation of the mixture revealed that the two products were present in approximately molecular proportions. Reduction of 4-Benzeneazo-5-methylglyoxaline. 3'7 Grams were triturated with 20 c.c. of hydrochloric acid and treated, as in the previous experiment, with 12 c.c. of stannous chloride solution. The insoluble stannichlorides amounted to 6'8 grams of moist material. Tin was removed, and the resulting solution evaporated under diminished pressure to low bulk, when the hydrochloride of the base, C9H]0ON2 (loc. cit., p. 254), separated, about 1-8 grams being obtained. The mother liquors eventually deposited ammonium chloride, and, on suitable treat¬ ment, yielded a small amount of aniline. The more soluble stanni¬ chlorides, when treated similarly, yielded a second hydrochloride, which separated as a matted mass of minute needles, readily soluble in water but sparingly so in alcohol. After recrystallisation from 10 per cent, hydrochloric acid, it darkened, but did not melt, at 300°. About 1‘2 grams were isolated.