Preparation and properties of 1:4(or 1:5)-dimethylglyoxaline and 1:3-dimethylpyrazole / by Hooper Albert Dickinson Jowett and Charles Etty Potter.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[between 1900 and 1909?]
Catalogue details

Licence: In copyright

Credit: Preparation and properties of 1:4(or 1:5)-dimethylglyoxaline and 1:3-dimethylpyrazole / by Hooper Albert Dickinson Jowett and Charles Etty Potter. Source: Wellcome Collection.

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    ether. The mother liquor, when treated with ether, gave a further quantity of methiodide, the total yield being almost quantitative. The methiodide, when purified by repeated crystallisation from alcohol and ether, forms white, prismatic needles which melt at 256°; it is very soluble in water and ethyl alcohol, less so in methyl alcohol, and quite insoluble in ether : 0*2374 required 10 c.c. iV/10 AgN03. 1 = 53*5. C5HsN2,CH3I requires 1 = 53*3 per cent. When subjected to dry distillation, the methiodide fused and decom¬ posed, giving the dimethylated base and methyl iodide. The base was separated from a certain amount of methiodide, which volatilised, by treating the distillate with dry ether, filtering, drying over potassium carbonate, and redistilling. After removing the ether, nearly all the residue distilled between 140° and 150°,the yield being theoretical. After twice fractionating, a portion boiling at 148° was analysed. It was a colourless, mobile liquid with a slight pyridine-like odour, and a burn¬ ing taste ; it was quite neutral to litmus, and had a sp. gr. =0*965 at 15°/15°. 0*1352 gave 0*3084 C02 and 0*1032 H20. C = 62*2 ; H = 8*5. 0*1062 „ 0*2440 C02 „ 0*0812 H20. C = 62*5 ; H = 8*5. 0*0610 ,, 14*6 c.c. nitrogen at 11° and 768 mm. N = 28*8. C5HgN2 requires C = 62*5; H = 8*3; N = 29*2 per cent. The ciurichloride, prepared in the ordinary way, crystallised in yellow needles, which softened at 165° and fused completely at 175°. The salt contains two molecules of water of crystallisation, which are lost, together with a molecule of hydrochloric acid, on heating at 115° : 0*1302 air-dried salt lost at 115° 0*0188 and gave 0*055 Au. Loss in weight = 14*4 ; Au = 42*2. C-H8N2,HAuC14,2H20 requires Au = 41*8 and for loss of 2H20,HC1 15*2 per cent. The platinichloride formed orange-coloured cubes which melted at 234°. The hydrochloride, obtained by evaporating the aqueous solution in a vacuum over caustic potash, separated in very hygroscopic, long, prismatic crystals ; it contained one molecule of water of crystallisa¬ tion and melted at 160°, but dissociated slowly on heating at 100°: 0 02 required 13*2c.c. W/10Na2CO3; C5H8N2,HC1,2H20requires 13*9 c.c.