Nitro-, arylazo-, and amino-glyoxalines / by Robert George Fargher and Frank Lee Pyman.

  • Fargher, Robert George.
Date:
[1919?]
Catalogue details

Licence: In copyright

Credit: Nitro-, arylazo-, and amino-glyoxalines / by Robert George Fargher and Frank Lee Pyman. Source: Wellcome Collection.

    34/44 (page 250)
    Owing to the formation of the bis-compound in the above reac¬ tion, the benzenediazonium chloride employed was insufficient to combine with the whole of the methylglyoxaline present, and it was calculated that 10'5 grams of this remained in the filtrate F. This was accordingly treated with a diazo-solution prepared from 11*9 grams of aniline, and gave further quantities of the substances described above, 5'3 grams of the bis-compound and 5'6 grams of 5-benzeneazo-4-methylglyoxaline being obtained in a nearly pure state. 2-Benzeneazo-^-methylglyoxaline (XIY, p. 224) crystallises from alcohol in orange prisms, which melt at 185° (corr.). Found: C=64'8; H = 5'6; N = 30'l. C10H10N4 (185'2) requires 0 = 64-5; H = 5*4; N = 30'l per cent. 5-Benzeneazo-k-methylglyoxaline (XVIII, p. 224) crystallises from alcohol in flat, glistening, copper-coloured needles, which melt and decompose at 240° (corr.). Found: C=64'5; H = 5-6; N = 30'0. C10H10N4 (185-2) requires 0 = 64*5; H = 5'4; N = 30'l per cent, 2 \'&-Bisbenzeneazo-k-methylglyoxaline separates from alcohol in prismatic needles and from ethyl acetate in cubes. Both forms are garnet-red in colour and melt and decompose at 206° (corr.). Found: C = 66'0, 65'9; H = 5*l, 5-1; N = 28'8, 28-8. 016Hi4N6 (290'2) requires 0 = 66-2; H=4’9; N = 29'0 per cent. This substance is readily soluble in alcohol, ethyl acetate, or acetone, fairly readily so in chloroform, but sparingly so in ether or benzene. It is soluble in aqueous sodium hydroxide, and is reprecipitated unchanged on the addition of acetic acid. It is only very sparingly soluble in dilute hydrochloric acid. When boiled with 10 per cent, aqueous hydrochloric acid, it is quickly resinified with effervescence, doubtless due to nitrogen, and the production of an odour of phenol. Reduction of 2-Benzeneazo-4-methyIglyoxaline with Stannous Chloride. 1*5 Grams of 2-benzeneazo-4-methylglyoxaline gave 1*4 grams of 2-amino-5-^-aminophenyl-4-methylglyoxaline dihydrochloride when reduced with stannous chloride in the manner previously described for the lower homologue (p. 238). 2-Amino-§-])-amino'phenyl - 4 - methylglyoxaline dihydro chloride crystallises from water in diamond-shaped plates, which are anhydrous and do not melt below 300°. It is readily soluble in cold, very readily so in hot water.